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/ /f 7 ^ Or, an Account of fome /i tx-r-tfY^' ^ 

Statical Experiments 




An Essay towards a Natural Hiftory of 
Vegetation: Of. Ufe to thofe who 
are curious in the Culture and Improve- 
ment of Gardening, &c. 


A Specimen of an Attempt to Analyfe the Air, 
by a great Variety of Chymio-Statical 
Experiments, which were read at feveral 
Meetings before the Royal Society. 

VOL. I. 

^uideji in bis, in quo non naturae ratio intelligent is appareat ? Nat. Deor. 
——Etenim Experimentorum longe w ajor eft fubtilitas y quam fenfus ipjius . 

Itaque eo rem deducimus, ut fenfus tantum de Experimento, Experimentum 

de rejitdicet. Fran, de Verul. Inftauratio magna. 

By STEPH. BALES, D, D. F. R. S. 

Rector of Faringdon^ Hampjhire^ and Minifter 
of Teddington, Middle/ex. 

The Third Edition, with Amendments. 


Printed fo> W. Innys and R. Manby, at the Weft-End of 
St. Paul's;' T.Woodward, at the Half-Moon ovcr-againft 
. St. Dunfian's Church in Fleet-ftreet ; and J. Pe el e, at Locke's 
Hetfti in Amm-Cormi . M . dc c. xxx nil. 

2 IE 5 5 

Feb. 1 6, 1726-7. Imprimatur. 

Isaac Newton, Pr.Reg.Soc, 


T O 

His Royal Highness. 


Prince of WALES. 

May it pleafe Tour fioyal Highnefs, 

I Humbly offer the following Expe- 
riments to Your Highnefs's Patro- 
nage, to proted; them from the 
reproaches that the ignorant are apt 
A 2 unrea- 


unreafonably to call on refearches of 
this kind, notwithftanding they are 
the only folid and rational means 
whereby we may ever hope to make 
any real advance in the knowledge 
of Nature : A knowledge, worthy the 
attainment of Princes. 

And as Solomon, the greateft and 
wifeft of men, difdained not to in- 
quire into the nature of Plants, from 
the Cedar in Lebanon, to the Hyjfop 
that fpringeth out of the wall : So it 
will not, I prefume, be an unaccept- 
able entertainment to Your Royal 
Highnefs, at leaft at Your leifure 
hours ; but will rather add to the 
pleafure, with which vegetable Na- 
ture in her prime verdure charms us : 
To fee the fteps fhe takes in her pro- 
ductions, and the wonderful power 
fhe therein exerts : The admirable 



provision fhe has made for them, not 
only vigoroufly to draw to great 
heights plenty of nouriihment from 
the earth ; but alfo more fublimed 
and exalted food from the air, that 
wonderful fluid, which is of fuch 
importance to the life of Vegetables 
and Animals ; and which, by infinite 
combinations with natural bodies, pro- 
duces innumerable furprizing effects, 
many inftances of which I have here 

The fearching into the works of 
Nature, while it delights and inlarges 
the mind, and ftrikes us with the 
ftrongeft aflurance of the wifdom and 
power of the divine Architect, in 
framing for us fo beautiful and well- 
regulated a world, it does at the fame 
time convince us of his conftant bene- 
volence and goodnefs towards us. 

A 3 That 


That this great Author of Nature 
may ftiower down on Your Royal 
Highnefs an abundance of his Blef- 
fings, both Spiritual and Temporal, 
is the fincere prayer of 

Tour Royal Highnefs s 
Mojl Obedient, 

Humble Servant \ 

Stephen Hales, 




THERE have been, within lefs 
than a Century, very great and 
ufeful dif cover ies made in the amazingly 
beautiful Jlruclure and nature of the 
animal economy ; neither have Plants 
pajfed unobferved in this inquifitive age, 
which has with fuch diligence extended 
its inquiries, infome degree, into almofl 
every branch of Nature s inexhauflible 
fund of wonderful works. 

We find in the Philofophical Tranf- 
aElions, and in the Hijlory of the Royal 
Academy of Sciences, accounts of many 
curious Experime?its and Obfervations 
made from time to time on Vegetables, 
by fever al ingenious and inquifitive Per- 
fons : But our country7nan Dr. Grew, 
0*fc/ Malpighi, were the firfi, who, tho 

A 4 in 

ii The Preface. 

in very dijlani countries, did nearly at 
the fame time, unknown to each other, 
engage in a very diligent and thorough 
inquiry into the JlruSlure of the vejfels 
of Plants ; a province, which till then 
had lai?i uncultivated. They have given 
us very accurate and faithful accounts 
of the flruElure of the parts, which they 
carefully traced, from their firft minute 
origin, the feminal Plants, to their full 
growth and maturity, thro their Roots, 
Trunk, Bark, Branches, Gems, Shoots, 
JLeaves, Bloffoms and Fruit. In all 
which they obferv d an exacl and regular 
fymmetry of parts mojl curioufly wrought 
in fuch manner, that the great work of 
Vegetation might effectually be carried 
on, by the uniform co-operation of the 
fever al parts, according to the different 
offices afftgned them by Nature. 

Had they fortuned to have fallen into 
this fat teal way of inquiry, perfons of 


The Preface. iii 

their great application andfagacity had 
doubtlefs made confiderable advances in 
the knowledge of the nature of Plants. 
This is the only fur e way to meafure the 
fever al quantities ofnourifhment, which 
Plants imbibe and perfpire, and thereby 
to fee what influence the different fates 
of Air have on them. This is the likeliefl 
method to find out the Sap's velocity , and 
the force with which it is imbibed : As 
alfo to ejlimate the great power that 
Nature exerts in extending and pufhing 
forth her produElions by the expanfion of 
the Sap. 

About twenty years fince, I made 
feveral hcemaflatical Experiments on 
Dogs ; and fix years afterwards re- 
peated the fame on Horfes and other 
Animals, in order to find out the real 
force of the blood in the Arteries, fome 
of which are mentioned in the third 
chapter of this book : At whicb times I 


iv The Preface. 

wiped I could have made the like Ex~ 
periments, to dif cover the force of the 
Sap in Vegetables ; but defpaired of 
ever efieEling it, till, about feven years 
fince, by mere accident I hit upon it<> 
while I was endeavouring by fever always 
to flop the bleeding of an old Jlem of a 
Vine, which was cut too near the bleed- 
ing feaf on, which I feared might kill it: 
Having, after other means proved inef- 
feSlual, tied a piece of bladder over the 
tranfverfe cut of the Stem, I found the 
force of the Sap did greatly exte?2d the 
bladder ; whence I concluded, that if a 
long glafs-tube were fixed there in the 
fame mamier, as I had before done to 
the Arteries of fever al living Animals, 
I fhould thereby obtain the real afc end- 
ing force of the Sap in that Stem, which 
fucceeded according to my expeSlation : 
and hence it is, that I have been irf en- 
fib ly led on to make farther a?id far- 

The Preface. v 

ther refearches by variety of Expert 

As the Art ofPhyfick has of late years 
been much improved by a greater know- 
ledge of the animal (economy ; fo doubt- 
lefs a farther infight into the vegetable 
eeconomy mufl needs proportionably im- 
prove our skill in Agriculture and Gar- 
denings which gives me reafon to hope y 
that inquiries of this kind will be accept- 
able to many, who are intent upon im- 
proving thofe innocent, delightful, and 
beneficial Arts : Since they cannot be in- 
fenfible, that the moft rational ground 
for Succefs in this laudable Purfuit mufl 
arifefrom a greater infight into the na- 
ture of Plants. 

Finding by many Experiments in the 

fifth chapter, that the Air is plentifully 

infpired by Vegetables, not only at their 

roots, but alfo thro feveral pjhrts of their 

trunks and branches ; this put ??}e upon 


vi The Preface. 

making a more particular inquiry into 
the nature of the Air, and to dif cover , 
if pojfible, wherein its great importance 
to the life and fupport of Vegetables 
might conftft ; on which account I was 
obliged to delay the Publication of the 
reft of thefe Experimettts, which were 
read two years Jince before the Royal So- 
ciety •, till I had made fome progrefs in 
this inquiry : An account of which I 
have given in the Jixth chapter. 

JVhere it appears by many chymio- 
ftatical Experiment s, that there is dif- 
fufed thro all natural mutually attraEl- 
ing bodies \ a large proportion of parti- 
cles ^ which ^ as the firft great Author of 
this important difcovery y Sir Ifaac 
Newton, obferves, are capable of being 
thrown off from denfe bodies by heat or 
fermentation into a vigoroufly elaftick 
and perma? / iently repelling ft ate ; and 
alfo of returning by fermentation, and 


The Preface, vii 

fometimes without it, into denfe bodies : 
It is by this amphibious property of the 
Air, that the main and principal ope- 
rations of Nature are carried on ; for 
a mafs of mutually attraSling particles y 
without being blended with a due pro- 
portion of elaflick repelling ones, would, 
in many cafes, foon coalefce into ajlug- 
gifh lump. It is by thefe properties of 
the particles of matter ', that he fo Ives 
the principal Phenomena of Nature. 
And Dr. Freind has from the fame 
principles given a very ingenious Ratio- 
nale of the chief operations in Chymiflry. 
It is therefore of importance to have 
thefe very operative properties of natu- 
ral bodies further afcertained by more 
Experiments and Obfervatio?ts : And it 
is with fatisfa&ion, that we fee them 
more and more confirmed to us, by every 
farther inquiry we make, as the follow- 
ing Experiments will plainly prove, by 


viii The Preface. 

Jhewing how great the power of the at- 
traEiio?i of acid fulphureous particles 
inujl be at fo?ne little diflance from the 
point of contaEi) to be able mojl readily 
tofubdue and fix elajlick aereal parti- 
cles y which repel with a force fuperior 
to vafil incumbent prejfures : Which 
particles we find are thereby changed 
from a ftrongly repelling^ to as firongly 
an attraSling Jlate : And that elafii- 
city is no immutable property of air, 
is further evident from thefe Experi- 
ments ; becaufe it were impojfible for 
fuch great quantities of it to be confined 
in the fubfiances of Animals and Vege- 
tables , in an elafiickfiate, without rend- 
ing their confiituent parts with a vafl 

I have been careful in making, and 

faithful in relating the refult of thefe 

Experiments ; and wijh I could be as 

happy in drawing the proper inferences 


The Preface. ix 

from them. However I may falljhort 
at jirji fetting out in this flatical way 
of inquiring into the nature of Plants^ 
yet there is good reafon to believe^ that 
conjiderable advances in the knowledge 
of their nature may, in procefs of time^ 
be 7nade by refearches of this kind. 

And I hope the publication of this 
Specimen of what I have hitherto done, 
will put others upon the fa7ne purfuits> 
there beings in fo large a fields and 
among fuch an innwnerable variety of 
fubje&S) abundant room for many heads 
and hands to be employed in the work : 
For the wonderful and fecret operations 
of Nature are fo involved and intricate y 
fo far out of the reach of our fenfes^ as 
they prefent themf elves to us in their na- 
tural order j that it is impojfible for the 
moft fagacious and penetrating Genius 
to pry into them y unlefs he will be at the 
paws of analyfmg Nature by a numerous 


x The Preface. 

and regular feries of Experiments^ which 
are the only Jolid fowtdation whence we 
may reafonably expeEl to make any ad- 
vance in the real knowledge of the ?iature 
cf things. 

I muft not omit here publiekly to ac- 
htowledge^ that I have in fever al refpeEls 
been much obliged to my late ingenious 
and learned neighbour and friend 'Robert 
Mather, of the Inner-Temple, Efq^for 
his afftflance herein. 

Whereas fome complain, that they do not under- 
fland the fignification of thofe fhort figns or 
characters, which are here made ufeof in many 
of the calculations, and which are ufual in 
Algebra ; this mark -f- fignifies more, or to be 
added to. Thus page 18, line 4, 6 ounces -j- 240 
grains, is as much as to fay, 6 ounces more by, 
or to be added to 240 grains. And in line 16, 
of the fame page, this mark x or crofs figni- 
fies multiplied by •, the two fhort parallel lines 
fignify equal to ; thus 1820 x 4= 7280 : 1, is 
as much as to fay, 1820 multiplied by 4 equal to 
7280 is to 1. 





Experiments, Jhewing the quantities of 
moijiure imbibed and perfpired by Plants 
and 'Trees. Page 4 


Experiments, whereby to find out the force 
with which Trees imbibe moijiure. 84 


Experiments, Jhewing the force of the fap in 
the Vine in the bleeding feajon. 108 


Experiments, Jhewing the ready lateral motion 
of the Sap, and confequently, the lateral 
communication of the Sap-ve'ffels. The free 
pajfage of it, from the fmall Branches to- 
wards the Stem, as well as from the Stem 
to the Branches, with an account of Jbme 
Experiments, relating to the Circulation, 
or Non-circulation of the Sap. 3 28 

a CHAP, 

The Contents. 


Experiments, whereby to prove, that a con* 

Jiderable quantity of air is infpired by 

Plants, 155 


A Specimen of an attempt to analyfe the Air 
by chymio-ftatical Experiments^ which Jhew 
in how great a proportion Air is wrought 
i?ito the compojition of Animal^ Vegetable, 
and Mineral Sub/lances : And withal, how 
readily it refumes its elajlick State, when 
in the dijfolution of thofe Sub/lances it is 
dif engaged from them. i6z 


Of Vegetation. 318 

The Conclujiou. 35? 

A Table where to find each Experiment, 



































45* 4 6 - 
















5 2 , 53. 54. 


13* I4> 


55> 5 6 - 








58, 59- 




60, 6i, 62. 




63, 6 4- 



5 2 

65, 66, 




67, 68, 69, 70. 








73> 74. 







9 1 









Exper. on Calc. 

} i93 





9 8 

78, 79. 




















85, 86. 











IJ 5 

9°> 9 1 - 


A Table where to find each Experiment. 





9 2 - 


1 10. 

















2 55 





9 g. 





















2 3I 



105, 106. 













• 2 39 

A Table 

where to 

find each Figure. 





I, 2. 




3> 4, 5- 


25, 26. 




27, 28, 

29, 30 

IS 2 

7> 8 > 9- 


3^3 2 - 


10, u> 12. 


33. 34- 


i3> 14. 


35* 3 6 > 



15, 16, 17, i 

S. 1 12 

3 s . 39- 






44. 346 

20, 21. 


45, 46. 


22, 23. 

J 3° 




TH E farther refearches we make in- 
to this admirable fcene of things* 
the more beauty and harmony we 
fee in them : And the ftronger and clearer 
convi&icns they give us, of the being, power 
and wifdom of the divine Architect, who 
has made all things to concur with a won- 
derful conformity, in carrying on, by va- 
rious and innumerable combinations of mat- 
ter, fuch a circulation of caufes and efFe&s, 
as was neceffary to the great ends of na- 

And fince wc are allured that the all-wife 
Creator has obferved the moil exadl propor- 
tions, of number , weight and meafure, in 
the make of all things ; the mbft likely way 
therefore, to get any infight into the na- 
ture of thofe parts" of the creation, whicl} 
come within our obfervation, muft in all 
reafon be to number, weigh and meafure- 
And we have much encouragement to pur- 

B fu* 

2 Vegetable Staticks. 

fue this method, of fcarching into the nature 
of things, from the great fuccefs that has 
attended any attempts of this kind. 

Thus, in relation to thofe Planets which 
revolve about our Sun, the great Philofo- 
pher of our age has, by numbering and 
meafuring, difcovered the exact proportions 
that are obferved in their periodical revo- 
lutions and diflances from their common 
centres of motion and gravity : And that 
God has not only comprehended the dujl 
of the earth in a meafure y and 'weighed the 
mountains in fcales, and the hills in a ba- 
lance^ Ifai. xl. j 2. but thathealfo holds the 
vaft revolving Globes, of this our folar Sy- 
ftem, moft exactly poifed on their common 
centre of gravity. 

And if we reflect: upon the difcoveries 
that have been made in the animal oecono- 
my, we fhall find that the moft confider- 
able and rational accounts of it have been 
chiefly owing to the ftatical examination 
of their fluids, viz. by inquiring what quan- 
tity of fluids, and folids diflblved into fluids, 
the animal daily takes in for its fupport 
and nouriihment : And with what force, 
and different rapidities, thofe fluids are car- 

Vegetable Stathks. 3 

ried about in their proper channels, accord- 
ing to the different fecretions that are to 
be made from them : And in what pro- 
portion the recrementitious fluid is convey- 
ed away, to make room for frefh fupplies; 
and what portion of this recrement nature 
allots to be carried off, by the feveral kinds 
of emunctories, and excretory dufts. 

And fince in vegetables, their growth, and 
the prefervation of their vegetable life, is 
promoted and maintained, as in animals, 
by the very plentiful and regular motion 
of their fluids, which are the vehicles or- 
dained by nature, to carry proper nutriment 
to every part ; it is therefore reafonable to 
hope, that in them alio, by the fame me- 
thod of inquiry, considerable difcoveries 
may in time be made, there being, in many 
refpedls, a great analogy between plants and 


4 Vegetable Staticks. 


Experiments, jhewing the quantities imbibed 
and perfpired by Plants and Trees. 

Experiment I. 

JUL Y 3. 1724. in order to find out the 
quantity imbibed and perfpired by the 
Sun-flower, I took a garden-pot (Fig. 1.) 
with a large Sun-flower, a, 3 feet-}-| high, 
which was purpofely planted in it when 
young; it was of the large annual kind. 

I covered the pot with a plate of thin 
milled lead, and cemented all the joints fill, 
fo as no vapour could pafs, but only air, thro' 
a fmall glafs tube d, nine inches long, which 
was fixed purpofely near the ftcm of the 
plant, to make a free communication with 
the outward air, and that under the leaden 

I cemented alfo another fhort glafs tube 
g into the plate, two inches long, and one 
inch in diameter. Thro' this tube I watered 
the plant, and then flopped it up with a 
cork ; I flopped up alfo the holes /, /, at the 
bottom of the pot with corks. 

I weighed 

Vegetable Static fa. 5 

I weighed this pot and plant morning 
and evening, for fifteen feveral days, from 
July 3. to Aug. 8. after which I cut off the 
plant clofe to the leaden plate, and then 
covered the ftump well with cement ; and 
upon weighing found there perfpired thro* 
the unglazed porous pot two ounces every 
twelve hours day ; which being allowed in 
the daily weighing of the plant and pot, I 
found the greateft perfpiration of twelve 
hours in a very warm dry day, to be one 
pound fourteen ounces; the middle rate of 
perfpiration one pound four ounces. The 
perfpiration of a dry warm night, without 
any fenfible dew, was about three ounces 5 
but when any fenfible, tho' fmall dew, then 
the perfpiration was nothing; and when a 
large dew, or fome little rain in the night, 
the plant and pot was increafed in weight 
two or three ounces. N. B. The weights 
I made ufe of were Avoirdupoife weights. 

I cut off all the leaves of this plant, and 
laid them in five feveral parcels, according 
to their feveral fizes ; and then meafured 
the furface of a leaf of each parcel, by lay- 
ing over it a large lattice made with threads, 
io which the little fquares were \ of an inch 
B ^ each* 

6 Vegetable Staticks. 

each 5 by numbring of which I had the iur- 
face of the leaves in fquare inches, which 
multiplied by the number of the leaves in 
the correfponding parcels, gave me the area 
of all the leaves; by which means I found 
the furface of the whole plant, above ground, 
to be equal to 5616 fquare inches, or 39 
fquare feet. 

I dug up another Sun-flower, nearly of 
the fame fize, which had eight main roots, 
reaching fifteen inches deep and fideways 
from the flem : It had befides a very thick 
bufh of lateral roots, from the eight main 
roots, which extended every way in a he- 
mifphere, about nine inches from the flem 
and main roots. 

In order to get an eftimate of the length 
of all the roots, I took one of the main roots, 
with its laterals, and meafured and weighed 
them ; and then weighed the other feven 
roots, with their laterals ; by which means 
I found the fum of the length of all the 
roots, to be no lefs than 1448 feet. 

And fuppofing the periphery of thefe 
roots, at a medium, to be 0.13 1 of an inch, 
then their furface will be 2276 fquare 
inches, or 15. 8 fquare feet; that is equal 


Vegetable Stoticks. 7 

to 0.4. of the furface of the plant above 

If, as above, twenty ounces of water, at 
a medium, perfpired in twelve hours day, 
(/. e.) thirty-four cubicle inches of water, (a 
cubick inch of water weighing 254 grains) 
then the thirty-four cubick inches divided 
by the furface of all the roots, is = 2286 
fquare inches ; (/. e.) -~js is = -~j; this gives 
the depth of water imbibed by the whole 
furface of the roots, viz ^ part of an 

And the furface of the plan: above ground 
being 5616 fquare inches, by which divide- 
ing the 34 cubick inches, viz. v|i6 ,3 = 1T7* 
this gives the depth perfpired by the whole 
furface of the plant above ground, viz. 7^7. 
part of an inch. 

Hence, the velocity with which water 
enters the furface of the roots to fupply the 
expence of perfpiration, is to the velocity, 
with which their fap perfpires, as 165 : 6j y 
or as F T T : ,^-j, or nearly as 5 : 2. 

The area of the tranfverfe cut of the mid- 
dle of the ftem is a fquare inch ; therefore 
the areas, on the furface of the leaves, the 
roots and ftem, are 5616, 2276. 1, 

B4 The 

8 Vegetable Statich. 

The velocities, in the furfaceof the leaves, 
roots, and tranfverfe cut of the ftem, are 
gained by a reciprocal proportion of the 

*g ^leaves — 5616 
3= 2276 

Now, their perfpiring 34 cubick inches in 
twelve hours day, there muft fo much pafs 
thro' the ftem in that time; and the velo- 
city would be at the rate of 34 inches in 
twelve hours, if the ftem were quite hollow. 

In order therefore to find out the quan- 
tity of folid matter in the ftem, July 2jth at 
7. a. m. I cut up even with the ground a 
Sun-flower; it weighed 3 pounds; in thirty 
days it was very dry, and had wafted in all 
2 pounds* 4 ounces ; that is | of its whole 
weight: So here is a fourth part left for 
folid parts in the ftem, (by throwing a piece 
of green Sun-flower ftem into water, I found 
it very near of the fame fpecifick gravity 
with water) which filling up fo muchofthe 
ftem, the velocity of the fap muft be increas- 
ed proportionably, viz. $ part more, (by 


Vegetable Staticks. 9 

reafon of the reciprocal proportion) that 34 
cubick inches may pafs the ftem in twelve 
hours ; whence its velocity in the ftem will 
be 45 | inches in twelve hours, fuppofing 
there be no circulation, nor return of the 
lap downwards. 

If there be added to 34, (which is theleaft 
velocity) -j of it = 1 1 -j, this gives the greateft 
velocity, viz. 45-j. The fpaces being as 3 : 4. 
the velocities will be 4 : 3 :: 454-: 34. 

But if we fuppofe the pores in the fiirfacc 
of the leaves to bear the fame proportion, 
as the area of the fap-veffels in the ftem do 
to the area of the ftem; then the velocity, 
both in the leaves, root and ftem, will be 
increafed in the fame proportion. 

A pretty exaft account having been taken, 
of the weight, iize, and furface of this 
plant, and of the quantities it has imbibed 
and perfpired, it may not be improper here, 
to enter into a comparifon, of what is taken 
in and perfpired by a human body, and this 

The weight of a well-fized man is equal 
to 160 pounds: The weight of the Sun- 
flower is 3 pounds ; fo their weights are to 
cash other as 160:3, or as 53: 1. 


io Vegetable Statu ks. 

The lurface of fiich human body is equal 
to 15 fquare feet, or 2160 fquare inches. 

The furface of the Sun-flower is 5616 
fquare inches 5 fo its furface is, to the furface 
of a human body, as 26 : 10. 

The quantity perfpired by a man in twenty- 
four hours is about 3 1 ounces, as Dr. Keill 
found. Vid. Medic. Stai.Britan. p. 14. 

The quantity perfpired by the plant, in 
the fame time, is 22 ounces, allowing two 
ounces for the perfpiration of the beginning 
and ending of the night in July, viz. after 
evening, and before morning weighing, juft 
before and after night. 

So the perfpiration of a man to the Sun- 
flower is as 141 : 100. 

Abating the fix ounces of the thirty-one 
ounces, to be carried off by refpiration from 
the lungs in the twenty-four hours ; ( which 
I have found by certain experiment to be fo 
much, if not more ) the twenty-five ounces 
multiplied by 43 8> the number of grains 
in an ounce Avoirdupois, the producl: is 
10950 grains; which divided by 254, the 
number of grains in a cubick inch of water, 
gives 43 cubick inches perfpired by a man : 
which divided by the furface of his body, 


Vegetable Staticks. 1 1 

viz. 2160 fquare inches, the quotient is near- 
ly y_ part of a cubick inch perfpired off a 
fquare inch in twenty-four hours. Therefore 
in equal furfaces, and equal times, the man 
perfpires f , the plant 7 £ T , or as 50 : 15. 

Which excefs in the man is occafioned 
by the very different degrees of heat in each: 
For the heat of the plant cannot be greater 
than the heat of the circumambient air, 
which heat in Summer is from 25 to 35 de- 
grees above the freezing point, {vide Exp. 
20.) but the heat of the warmeft external 
parts of a man's body is 54 fuch degrees, 
and the heat of the blood 64 degrees; 
which is nearly equal to water heated to 
fuch a degree as a man can well bear to hold 
his hand in, ffirring it about 5 which heat is 
fufficient to make a plentiful evaporation. 

£>u. Since then the perfpirations of equal 
areas in a man and a Sun-flower, are to each 
other as 165 : 50, or as 3 JL : 1 ; andfincethp 
degrees of heat areas 2 : 1, muff not thefum 
or quantity of the areas of the pores lying 
in equal furfaces, in the man and Sun-flower, 
be as 1 2. : 1 ? for it feems that the quantities 
of the evaporated fluid will be as the degrees 
of heat, and the fum of the areas of the pores, 
taken together. Dr. 

12 Vegetable Staticks. 

Dr. Keill, by eftimating the quantities of 
the feveral evacuations of his body, found 
that he eat and drank every 24 hours, 4 
pounds 10 ounces. 

The Sun-flower imbibed and perfpired in 
the fame time 22 ounces 5 fo the man's food, 
to that of the plant, is as 74 ounces to 22 
ounces, or as 7:2. 

But compared bulk for bulk, the plant im- 
bibes 17 times more frefti food than the man: 
For deducing 5 ounces, which Dr. Keill al- 
lows for the faces ahi, there will remain 4 
pounds 5 ounces of frefh liquor, which en- 
ters a mans veins; and an equal quantity 
paffes off every 24 hours. Then it will be 
found, that 17 times more new fluid enters 
the fap-veffels of the plant, and paffes off in 
24 hours, than there enters the veins of a 
man, and paffes off in the fame time. 

And fince, compared bulk for bulk, the 
plant perfpires feventeen times more than 
the man, it was therefore very neceffary, by 
giving it an extenfive furface, to make a large 
provifion for a plentiful perfpiration in the 
plant, which has no other way of dis- 
charging fuperfluities 5 whereas there is pro- 
vifion made in man, to carry off above 


Vegetable Staticks. 13 

half of what he takes in, by other eva- 

For fince neither the furface of his body 
was extenfive enough to caufe fufficient ex- 
halation, nor the additional wreak, arifing 
from the heat of his blood, could carry off 
above half the fluid which was neceflary to 
be difcharged every 24 hours; there was a 
neceffity of providing the kidneys, to per- 
colate the other half through. 

And whereas it is found, that 17 times 
more enters, bulk for bulk, into the fap-vef- 
fels of the plant, than into the veins of a man, 
and goes off in 24 hours: One reafon of 
this greater plenty of frefh fluid in the vege- 
table than the animal body, may be, becaufe 
the fluid which is filtrated thro' the roots im- 
mediately from the earth, is not near fo full 
freighted with nutritive particles as the chyle 
which enters the lacteals of animals 5 which 
defect it was neceffary to fupply by the en- 
trance of a much greater quantity of fluid. 

And the motion of the fap is thereby much 
accelerated, which in the heartlefs vegetable 
would otherwife be very flow; it having 
probably only a progreffive, and not a circu- 
lating motion, as in animals. 


14 Vegetable Staticks. 

Since then a plentiful perfpiration is 
found fo neceffary for the health of a plant 
or tree, 'tis probable that many of their dis- 
tempers are owing to a ftoppage of this per- 
fpiration, by inclement air. 

The perfpiration in men is often flopped 
to a fatal degree ; not only by the inclemen- 
cy of the air, but by intemperance, and vio- 
lent heats and colds. But the more tempe- 
rate vegetables perfpiration can be flopped 
only by inclement air -, unlefs by an un- 
kindly foil, or want of genial moifture, it is 
depriv'd of proper or fufficient nourishment. 
As Dr. Keill obferv'd in himfelf a con- 
fiderable latitude of degrees of healthy per- 
fpiration, from a pound and a half to 3 pounds ; 
I have alfo obferved a healthy latitude of 
perfpiration in this Sun-flower, from 16 to 
28 ounces, in twelve hours day. The more 
it was watered, the more plentifully it per- 
fpired, (ceteris paribus ) and with fcanty 
watering the perfpiration much abated. 

Experiment II. 

From July 3d. to Aug. 3d. I weighed 
for nine feveral mornings and evenings a 


Vegetable Staticks. 1 5 

middle- fized Cabbage plants which grew in 
a garden pot, and was prepared with a leaden 
cover, as the Sun-flower, Exper. ijl. Its 
greater! perfpiration in twelve hours day 
was 1 pound 9 ounces; its middle perfpira- 
tion 1 pound 3 ounces, = 32.7 cubick inches* 
Its furface 2736 fquare inches, or 19 fquare 
feet. Whence dividing the 32 cubick inches 
by 2736 fquare inches, it will be found 
that a little more than the— of an inch 
depth perfpires off its furface in twelve hours 

The area of the middle of the Cabbage 
flem is -ff|- of a fquare inch ; hence the ve- 
locity of the fap in the ftem is, to the ve- 
locity of the perfpiring fap on the furface 
of the leaves, as 2736 : |££ : : 4268 : 1 . 

for i!36Ji_LL 6 68. But if an allow- 

ioo T 

ance is to be made for the folid parts of the 

flem, (by which the paffage is narrowed) the 

velocity will be proportionally increafed. 

The length of all its roots 470 feet, their 

periphery at a medium ~ T of an inch, hence 

their area will be 256 fquare inches nearly; 

which being fo frnall in proportion to the 

area of the leaves, the fap muft go with 


\6 Vegetable Staticks. 

above ten times the velocity through the 
furfdce of the roots, that it does thro* the 
furface of the leaves. 

And fetling the roots, at a medium, at 12 
inches long, they muft occupy a hemifphere 
of earth two feet diameter, that is, 2.r cu- 
bick feet of earth. 

By comparing the furfaces of the roots of 
plants, with the furface of the fame plant 
above ground, we fee the neceifity of cut- 
ting off many branches from a tranfplanted 
tree: For if 256 fquare inches of root in 
furface was neceffary to maintain this Cab- 
bage in a healthy natural ftate: fuppofe, upon 
digging it up, in order to tranfplant, half the 
roots be cut off, ( which is the cafe of moft 
young tranfplanted trees) then it's plain, that 
but half the ufual nourifliment can be car- 
ried up through the roots on that account ; 
and a very much lefs proportion on account 
of the fmall hemifphere of earth, the new 
planted fhortened roots occupy ; and on ac- 
count of the loofe pofition of the new turn- 
ed earth, which touches the roots at firft 
but in few points. This (as well as experi- 
ence) ftrongly evinces the great neccffity of 

well watering new plantations. 


Vegetable Stathks* \f 

Which yet muft be done with caution, for 
the skilful and ingenious Mr. Philip Miller 
F. R. S. Gardener of the Botanick garden at 
Cbelfea, in his very ufeful Gardeners Dicti- 
onary, fays, <c As to the watering of all new* 
<c planted trees, I mould advile it to be done 
" with great moderation, nothing being 
<c more injurious to them than over-water- 
<c ing of them. Vide Planting!' And I ob- 
served, that the dwarf pear-tree, whofe root 
was fet in water, in Exper. 7. decreafed very- 
much daily in the quantity imbibed ; viz. be- 
caufe the fap-veffels of the roots, like 
thofe of the cut off boughs, in the fame 
Experiment, were fo faturated and clogged 
with moifture, by ftanding in water, that 
more of it could not be drawn up to fup*, 
port the leaves* 

Experiment IIL 

From July 28. to Aug. 25. 1 weighed for 
twelve feveral mornings and evenings, a 
thriving Vine growing in a pot ; I was fur- 
niflied with this and other trees, from his 
Majefty's garden at Hampton-court , by the 

C favour 

18 Vegetable Statich. 

favour of the eminent Mr. Wife. This 
vine was prepared with a cover, as the Sun- 
flower was. Its greateft perfpiration in 12 
hours day, was 6 Ounces + 240 grains; its 
middle perfpiration 5 ounces -\- 240 grains 
— 10 g~ cubick inches. 

The fur face of its leaves was 1820 fquare 
inches, or 12 fquare feet +92 fquare 
inches; whence dividing g\ cubick inches, 
by the area of the leaves, it is found that 
-^j part of an inch in depth, perfpires off in 
12 hours day. 

The area of a tranfverfe cut of its ftem, 
was equal to 4- of a fquare inch: hence the 
fap's velocity here, to its velocity on the fur- 
face of the leaves, w 7 ill be as 1820 x 4 = 
7280 : 1. Then the real velocity of the fap's 
motion in the ftem is = 7 ^f =38 inches 
in twelve hours. 

This is lbppoiing the ftem to be a hollow 
tube: but by drying a large vine-branch, (m 
the chimney corner) which I cut off in the 
bleeding feaibn, I found the folid parts were 
•f of the ftem ; hence the cavity thro* which 
the fap paflte, being fo much narrowed, its 
velocity will be 4 times as great, viz. 152 

inches in 12 hours. 


Vegetable Statich. 19 

But it is further to be confidered, that if 
the lap moves in the form of vapour, and 
not of water, being thereby rarefied, its ve- 
locity will be increafed in a direct propor- 
tion of the fpaces, which the fame quan- 
tity of water and vapour would occupy 5 
And if the vapour is fuppofcd to occupy 10 
times the fpace which it did, when in the 
form of water, then it muft move ten times 
fafler; fo that the fame quantity or weight 
of each may pafs in the fame time, thro* 
the fame bore or tube : And fuch allow- 
ance ought to be made in all thefe calcu- 
lations concerning the motion of the fap in 

Experiment IV. 

From July 29. to Aug. 25. I weighed 
for 12 feveral mornings and evenings, a pa- 
radife flock Apple-tree, which grew in a 
garden por, covered with lead, as the Sun- 
flower : it had not a bufhy head full of 
leaves, but thin fpread, being in all but 163 
leaves, whofe furface was equal to 1589 
fquare inches, or 1 1 fquare feet + 5 fquare 

C 2 The 

io Vegetable Staticks. 

The greateil quantity it perfpired in 12 
hours day, was 1 1 ounces, its middle quan- 
tity 9 ounces, or 15 \ cubick inches. 

The 15- cubick inches perfpired, divided 
by the furface 1589 fquajre inches, gives the 
depth perfpired off the furface in 12 hours 
day, viz. -—r of an inch. 

The area of a tranfverfe cut of its fiem, \ of 
an inch fquare, whence the fap's velocity 
here, will be to its velocity on the furface 
of the leaves, as 1589 x 4 = 6356:1. 

Experiment V. 

From Jit ly 28. to Aug. 25. I weighed for 
10 feveral mornings and evenings a very 
thriving Limon-tree, which grew in a gar- 
den pot, and was covered as above: Its great- 
eft perfpiration in 12 hours day was 8 ounces, 
its middle perfpiration 6 ounces, equal to 
ic-J cubick inches, In the night it perfpired 
fometimes half an ounce, fometimes nothing, 
and fometimes increafed 1 or 2 ounces in 
weight, by large dew or rain. 

The furface of its leaves was 2557 
fquare inches; or 17 fquare feet ~p 109 
fquare inches; diyiding then the 10 cubick 
inches perfpired by this furface, gives the 



So the feveral fore- 
going perfpirations 
in equal areas are, 

Vegetable Statkh. 
depth perfpired in 12 hours day, viz. T |j 
of an inch. 

-~ T in the vine in 12 
hours day. 

jo- in a man, in a day 
and a night. 
T £ T in a fun -flower, 
in a day and night. 
jo in a cabbage, in 1 % 
hours day. 

T £- in an apple- tree, 
in 12 hours day. 
-j^ in a limon-tree, 
in 12 hours day. 
The area of the tranfverfe cut of the Hem 
of this Limon-tree was — 1 44 of a 
fquare inch ; hence the fap's velocity here, 
will be to its velocity on the furface of the 

leaves, as 1768: 1 for 2 * 57 x IOO = 17- 7 
J 144 

This is fuppofing the whole ftem to be a hol- 
low tube; but the velocity will be increafed 
both in the ftem and in the leaves, in propor- 
tion as the paffagc of the fap is narrowed by 
the folid parts. 

By comparing the very different degrees 
of perfpiration, in thefe 5 plants and trees* 

C 3 we 

2 1 Vegetable Staticks. 

we may obferve, that the Limon-tree, which 
is an ever-green, perfpires much lefs than the 
Sun-flower, or than the Vine or the Apple- 
tree, whofe leaves fall off in the winter; 
and as they perfpire lefs, fo are they the 
better able to furvive the winter's cold, 
becaufe they want proportionably but a very 
fmall fupply of frcuh nourifhment to fup- 
port them ; like the exangueous tribe of 
animals, fiogs, toads, tortoifes, ferpents, 
infecls, &c. which as they perfpire little, 
fo do they live the whole winter without 
food. And this I find hold true in 12 
other different forts of ever-greens, on which 
I have made Experiments. 

The above- mention'd Mr. Miller made 
the like Experiments in the Botanick-gar- 
den at Cbelfea, on a Plantain-tree, an Aloe, 
and a Paradife Apple-tree; which he weigh- 
ed morning, noon, and night, for feveral 
fuccefiive days. I ihall here infert the di- 
aries of them, as he communicated them to 
mc, that the influence of the different tem- 
peratures of the air, on the perfpiration of 
thtfe plants, may the better be feen. 

The pots which he made ufe of were 
glazed, and had no holes in their bottoms as 


Vegetable Staticks. 25 

garden pots ufually have 3 fo that all the 
moifture, which was wanting in them upon 
weighing, muft neceflarily be imbibed by 
the roots of thofe plants, and thence per- 
fpired off thro' their leaves. 

A Diary of the perfpiration of the Mufa Ar- 
bor, or Plantain-tree of the Weft-Indies. 
The whole furface oj the plant was 14 
fquare feet^ 8 + \ inches. The different 
degrees of heat of the air are here noted 
by the degrees above the freezing point in 
my Thermometer, defcritid in Exper. 20. 

1726 Weigh 
at 6 





2 3 

pd. ou 

38 S 
37 ij 

37 4 

36 14 
36 10 

36 14 
36* 6 

at 12 
pd. ou. 
38 o 


37 Si*? 

37 * 

36 12 

37 o 

3* rt 




at 6 

pd. ou. 

37 H 

37 3i 

37 ° 

36 n 
36 15- 

36 n£ 






This evening T2 ounces of water were poured 
removed from the ftove into a cool room, where 
Sun, the windows being North-weft. 

C 4 

M B. This plant 
flood in a ftove, with a 
fmall fire in it $ the af- 
pedt of the ftove was 
South- eaft. 

A hot clear day. Thi 
morning he obferve 
large drops of water a 
the extremity of ever 
leaf, and we may obferve 
that it perfpires very 
much this day, 
J An extreme hot clear 

Moderately hot, but clear. 
This morn. 12, ounces of 
water poured into the 
pot. Mixture of Sun and 

Much thunder, fome rain 
and hail at a diftance. 
A gloomy day, but no 

into the potj and it was 
it had a free air, but no 


2 4 

Vegetable Statich. 








ac 6 





at 6 









pd. OU. 



pJ. ou. 



27 OO 





36 irf 


Calm cloudy weather. 


37 00 





36 13 


A pretty clear day. 


36 12 



1 1 


36' 10 

24 1 

A hot day. 


36 IC-7 





36 6 

l /i 

A very hot day. 


36 6~ 





S^ 3z 

2 3 

Some rain and cloudy. 
At this time, the under 
leaves of the plant be- 
gan to witherand decay ; 
^nd the top leaf" to un- 
fold, and fpread abroad j 
butthey are obferved ne- 
ver to grow bigger, af- 




36 2 
36 |£ 

T 9 





36 1 



tei they arefully opened. 
A temperate day. 
Temperate weather not^ 
very clear. 


ur ■* 





3T «3l 


Some rain. The whole 
plant begins to change 
colour, and appear fickly, 


$* «* 



11 2 

2 3 

35- 11 


He then removed the 
plant imp the ftove again 
in order to recover it j 
but it continued to fade, 
and in 2 or 5 days died. 

3f 10 





3f »i 


A cool and cloudy dav. 


35- co 

** Si 


3 * 

34 M 

1 9 1 A warm day : and the 





whole plant decayed. 

We may obferve from this diary, that 
this plant, when in the ftove, ufually per- 
fpired more in fix hours before noon than 
in fix hours after noon ; and that it perfpired 
much lefs in the night, than in the day time : 
And fometimes increafed in weight in the 
night, by imbibing the moifture of the 
ambient air j and that both in the ftove and 


Vegetable Statich. 25 

in the cool room. Upon making an eftimate 
of the quantity perfpired off a fquare inch of 
this plant, in 1 2 hours day, it comes but to 
T yT of a cubick inch, on the 18 th day of 
May, when by far its greateft perfpiration was $ 
for on feveral other days it was much lefs. 

A Diary of the Aloe Africana Caulefcens 
foliis fpinofis, maculis ab utraque parte al- 
bicantibus not at is, Commelini Hort. Amjl. 
commonly called the Carolina Aloe. 7/ 
was a large plant of its kind. It food 
in a glafs-cafe y which had a South afpeSi 
without a fire. 






1 at 6 | 

at 1 2 | q 

at 6 



Morn. ! 3 

Noon. J 2 



pd. ou. 1 ' 



4.1 6 if 

41 2^36 

-M 3 



+ i 1728^ 

40 14 j2.i£ 

4.0 1 2 



<J.O I2jl6£ 

40 10 '31 

40 8i;2 9 A 


40 Q-I27 

40 6\ 30 

40 ^28 


40 6 


40 rf 


40 4 



41 10 


ft* H 



" 4 

This evening promif- 
ingfome rain, he fet the 
pot out to receive a little j 
and then wiping the 
leaden furnace of the pot 
dry, he fet it into the 
glafs-cafe again. 

Now the pot broke, 
and hindered any fur- 
ther obfervations. 

We may obferve, that tms Aloe increafed 
in weight moll nights, and perfpired moil in 
the morning. A Diary 

26 Vegetable Statkks. 

A Diary of a fmall Parad ife- Apple, with one 
Upright ft em 4 feet high; and two fmall 
lateral branches about 8 inches long. This 
plant food under a cover of wood, which 
was open on all fides. 



J 9 



36 12 

16 7 

3« 3^ 

36 OO 

IS 4 

J 4 










37 3 

36 14. 

36 ioj 

3<* T 

36 1 


IS *3 

34 6i 


3 + 

IS Sh^ 

37 1 !*o I 

36 13^19 The leaves very dry, 
36 9 J20i a nd become fpeckled for 
a, 120 jwant of dew. 
2 J.' x 2I.I Then he removed the 
^ .'plant into the ftove, to 
try what efFedt that 
would have on its per- 

At this time the leaves 
were withered with the 
heat, and hung down 
as if they would fall off". 
At this time feveral 
of the leaves began to 
fall off. 

All the leaves fallen 
off, except a few fmall 
ones, at the extremities 
of the branches which 
had put out, fince the 
plant was in the ftove. 
The earth it ftood in 
was very moift all the 

IS 00 



In OBober 1J25. Mr. Miller took up an 
African Briony-root, which when cleared 
from the mould, weighed eight ounces i-j 
he laid it on a fhelf in the ftove, where it 
remained till rfie March following; when 
upon weighing he found it had loft of its 


Vegetable Staticks. 27 

weight. In April it fhot out 4 branches, 
two of which were £| feet long, the other 
two were one of them 14 inches, the other 
9 inches, in length : Thefe all produced 
fair large leaves. It had loft i| ounce in 
weight, and in three weeks more it loft 
2\ ounces more, and was much withered. 

Experiment VI. 

Spear-mint being a plant that thrives mod 
kindly in water, ( in order the more ac- 
curatelv to obferve what water it would 
imbibe and perfpire by night and day, in 
wet or dry weather ) I cemented at r a plant 
of it m. into the inverted fyphon ryxb 
( Fig. 2.) The fyphon was \ inch diam. at b 9 
but larger at r. 

I filled it full of water, the plant imbibed 
the water fo as to make it fall in the 
day (in March) near an inch and half from 
b to t, and in the night £ inch from t to i : 
but one night, when it was fo cold, as to 
make the Thermometer fink to the freezing 
point, then the mint imbibed nothing, but 
hung down its head; as did alfo the young 
beans in the garden, their fap being great- 

1 8 Vegetable Stattcks. 

ly condenfed by cold. In a rainy day the 
mint imbibed very little. 

I purfued this Experiment no farther, Dr. 
Woodward having long fince, from feveral 
curious experiments and obfervations, given 
an account in the Philofophical Tranfaftions, 
of the plentiful perfpirations of this plant. 

Experiment VIL 

In Augufl, I dug up a large dwarf Pear- 
tree, which weighed 71 pounds 8 ounces; 
I fet its root in a known quantity of wa- 
ter - y it imbibed 15 pounds of water in ten 
hours day, and perfpired at the fame time 
15 pounds 8 ounces. 

In July and Augujl I cut off feveral 
branches of Apple-trees, Pear, Cherry, and 
Apricot-trees, two of a fort ; they were of 
feveral fizes from 3 to 6 feet long, with pro- 
portional lateral branches ; and the tranfverfe 
cut of the largeft part of their ftems was 
about an inch diameter. 

I ftripped the leaves off of one bough of 

each fort, and then fet their ftems in fepa- 

rate glaffes, pouring in known quantities of 



Vegetable Stathh. tp 

The boughs with leaves on them im- 
bibed fome 15 ounces, fome 20 ounces 
25 or 30 ounces in 12 hours day, more or 
lefs, in proportion to the quantity of leaves 
they had ; and when I weighed them at night, 
they were lighter than in the morning. 

While thofe without leaves imbibed but 
one ounce, and were heavier in the even- 
ing than in the morning, they having per- 
fpired little. 

The quantity imbibed by thofe with leaves 
decreafed very much every day, the fap- 
veffels being probably fhrunk at the tranf- 
verfe cut, and too much faturate with wa- 
ter, to let any more pafs ; fo that ufually in 
4 or 5 days the leaves faded and withered 

I repeated the fame Experiment with Elm- 
branches, Oak, Ofier, Willow, Sallow, 
Afpen, Curran, Goosberry, and Philbert 
branches; but none of thefe imbibed fo 
much as the foregoing, and feveral forts of 
ever-greens very much lefs. 

Experiment VIII. 
Angufi 15. I cut off a large Rujet-pipin, 
with two inches item, and its 12 adjoining 


30 Vegetable Staticks. 

leaves ; I fet the ftem in a little phial of wa- 
ter : it imbibed and perfpired in three days 
|- of an ounce. 

At the fame time I cut off from the fame 
tree another bearing twig of the fame length, 
with 12 leaves on it, but no apple; it im- 
bibed in the fame three days near | of an 

About the fame time I fet in a phial of 
water a fhort ftem of the fame tree, with 
two large Apples on it without leaves; they 
imbibed near \ ounce in two days. 

So in this Experiment, the apple and the 
leaves imbibe -f- of an ounce; the leaves 
alone near -f , but the two large apples im- 
bibed and perfpired but \ part fo much as the 
12 leaves; tlien one apple imbibed the ~ part 
of what was imbibed by the 12 leaves; there- 
fore two leaves imbibe and perfpire as much 
as one apple; whence their perfpirations 
feem to be proportionable to their furfaces -, 
the furface of the apple being nearly equal 
to the fum of the upper and under furfaces 
of the two leaves. 

Whence it is probable, that the ufe of 
thefe leaves ( which are placed, juft where 
the fruit joins to the tree) is to bring nou- 


Vegetable Stattch. 31 

rifhment to the fruit. And accordingly I 
obferve, that the leaves, next adjoining to 
bloffoms, are, in the fpring, very much ex- 
panded, when the other leaves, on barren 
{hoots, are but beginning to (hoot: And 
that all peach leaves are pretty large before 
the bloffom goes off: And that in apples 
and pears the leaves are one third or half 
grown before the bloffom blows : So 
provident is nature in making timely pro- 
vifion for the nourifliing the yet embryo 

Experiment IX. 

July 15. I cut off two thriving Hop-vines 
near the ground, in a thick fhady part of 
the garden, the pole ftill ftanding; I ftrip- 
ped the leaves off one of thefe vines, and fet 
both their ftems in known quantities of 
water, in little bottles 5 that with leaves 
imbibed in 12 hours day 4 ounces, and that 
without leaves \ of an ounce. 

I took another hop-pole with its vines 
on it, and carried it out of the hop-ground, 
into a free open expofurej thefe imbibed 
and perfpired as much more as the former 


\i Vegetable Staticks. 

in the hop- ground: Which is doubtlefs 
the reafon why the hop-vines on the out- 
fides of gardens, where mod expofed to the 
air, are fhort and poor, in comparifon of 
thofe in the middle of the ground ; r ciz. be- 
caufe being much dried, their fibres harden 
fooner, and therefore they cannot grow fo 
kindly as thofe in the middle of the ground j 
which by (hade are always kept moifter, and 
more duftile. 

Now there being iooo hills in an acre 
of hop-ground, and each hill having three 
poles, and each pole three vines, the num- 
ber of vines will be 9000 -, each of which 
imbibing 4 ounces, the fum of all the ounces, 
imbibed in an acre in 12 hours day, will 
be 36000 ounces, = 15768000 grains = 
62047 cubick inches or 202 ale gallons; which 
divided by 6272640, the number of fquare 
inches in an acre, it will be found, that the 
quantity of liquor perfpired by all the hop- 
vines, will be equal to an area of liquor, 
as broad as an acre, and -—- part of an inch 
deep, befides what evaporated from the 

And this quantity of moifture in a kind- 
ly ftate of the air is daily carried off, in 

a fuffi- 

Vegetable Staticks. 3} 

a fufficient quantity, to keep the hops in 
a healthy (late $ but in a rainy moift ftate 
of air, without a due mixture of dry wea- 
ther, too much moifture hovers about the 
hops, fo as to hinder iri a good meafure the 
kindly perfpiration of the leaves, whereby 
the flagnating fap corrupts, and breeds mol- 
dy fen, which often fpoils vaft quantises of 
flourishing hop-grounds. This was the cafe 
in the year 1723, when 10 or 14 days al- 
moft, continual rains fell, about the latter 
half of July, after four months dry weather; 
upon which the moft flouriming and pro- 
mifing hops were all infected with mold or 
fen, in their leaves and fruit, while the then 
poor and unpromifing hops efcaped, and pro- 
duced plenty ; becaufe they being fmall, did 
hot perfpire fo great a quantity as the others; 
nor did they confine the perfpired vapour, io 
much as the large thriving vines did, in their 
fhady thickets. 

This rain on the then warm earth made 
the grafs moot out as faft as if it were in a 
hot-bed ; and the apples grew fo precipi- 
tately, that they were of a very flamy conlli- 
tution, fo as to rot more remarkably than 
had ever been remembred. 

D The 

34 Vegetable Statkks. 

The planters obferve, that when a mold or 
fen has once feized any part of the ground, it 
foon runs over the whole; and that the grafs, 
and other herbs under the hops, are infected 
with it. 

Probably becaufe the fmall feeds of this 
quick growing mold, which foon come to 
maturity, are blown over the whole ground: 
Which fpreading of the feed may be the 
reafon why fome grounds are infected with 
fen for feveral years fucceffively ; viz. from 
the feeds of the laft year's fen: Might it not 
then be advifeable to burn the fenny hop- 
vines as foon as the hops are picked, in hopes 
thereby to deftroy fome of the feed of the 
mold ? 

u Mr. Aujlin of Canterbury obferves fen 
" to be more fatal to thofe grounds that 
fl are low and iheltered, than to the high 
" and open grounds; to thofe that are fhelv- 
M ing to the North, than to the (helving 
" to the South ; to the middle of grounds, 
" than to the outrides; to the dry and 
11 gentle grounds, than to the moift and ftifF 
" grounds. This was very apparent through - 
cc out the Plantations, where the land had 
tJ the fame workmanfhip and help beflowed 

" upon 

Vegetable Statich. 35 

€c upon it, and was wrought at the fame 
lc time j but if in either of thefe cafes there 
" was a difference, it had a different effed: ; 
" and the low and gentle grounds, that lay 
" neglected* were then feen tefs diftempered 
" than the open and moift, that were care* 
" fully managed and looked after. 

" The honey dews are obferved to come 
<c about the i ith of June, which by the mid- 
<c die of July turn the leaves black, and make 
« them ftink." 

I have in July (the feafon for fire-blafts* 
as the planters call them) feen the vines in 
the middle of a hop-ground all fcorehed 
up, almoft from one end of a large ground 
to the other, when a hot gleam of Sun* 
ihine has come immediately after a fhower 
of rain ; at which time the vapours are of- 
ten feen with the naked eye, but efpecially 
with reflecting Telefcopes, to afcend to 
plentifully, as to make a clear and diftind: 
objedt become immediately very dim and 
tremulous. Nor was there any dry gravelly 
vein in the ground, along the courfe of this 
fcorch. It was therefore probably owing 
to the much greater quantity of torch- 
ing vapours in the middle than outlides of 

D 2 the 

$6 Vegetable Staticks. 

the ground ; and that being a denfer me- 
dium, it was much hotter than a more rare 

And perhaps, the great volume of amend- 
ing vapour might make the Sun-beams con- 
verge a little toward the middle of the ground, 
that being a denfer medium, and thereby 
increafe the heat considerably ; for I obferv- 
ed, that the courfe of the fcorched hops 
was in a line at right angles, to the Sun- 
beams about eleven o' clock, at which time 
the hot gleam was: The hop-ground was 
in a valley which run from South-weft to 
North-eaft: And, to the beftof my remem- 
brance, there was then but little wind, and 
that in the courfe of the fcorch ; but had 
there been" fome . other gentle wind, either 
North or South, 'tis not improbable but 
that the North wind gently blowing the 
volume of rinng wreak on the South fide 
of the ground, that fide might have been 
moft fcorched, and fo vice verfd. 

As to particular fire-blafts, which fcorch 
here and there a few hop-vines, or one or 
two branches of a tree, without damaging 
the next adjoining; what Jljlronomers ob- 
ferve, may 'hint to us a no very improbable 


Vegetable Staticks. 37 

caufe of it; viz. they frequently obferve 
(efpecially with the reflecting Telefcopes ) 
fmall feparate portions of pellucid vapors 
floating in the air; which tho' not vifible to 
the naked eye, are yet confiderably denfer 
than the circumambient air : And vapors of 
fuch a degree of denfity may very proba- 
bly, either acquire fuch a fcalding heat from 
the Sun, as will fcorch what plants they 
touch, efpecially the more tender : an effect 
which the gardeners about London have too 
often found to their coft, when they have 
incautioufly put bell-glafTes- over their col- 
lyflowers early in a frofty morning, before 
the dew was evaporated off them; which 
dew being raifed by the Sun's warmth, and 
confined within the glafs, did there form a 
denfe tranfparent fcalding vapor, which burnt 
and killed the plants. Or perhaps, the up- 
per or lower furface of thefe tranfparent fe- 
parate flying volumes of vapors may, among 
the many forms they revolve into, fometimes 
approach fo near to a hemifphere, or hemi- 
cylinder, as thereby to make the Sun-beams 
converge enough, often to fcorch the more 
tender plants they fhall fall on : And fome- 
times alfo, parts of the more hardy plants 

D 3 and 

1 8 fegetabh Statkh. 

and trees, in proportion to the greater or Iefs 
convergence of the Sun's rays. 

The learned Boerhaave^ in his Theory of 
CkeTniftry, Dr. Shaw's Edition, p. 245. ob- 
ferves, " That thofe white clouds which ap- 
cc pear in fummer-time, are, as it were, fo 
11 many mirrors, and occafion exceffive heat. 
} x Thefe cloudy mirrors are fometimes round, 
" fometimes concave, polygonous, &c. When 
cc the face of heaven is covered with fuch 
" white clouds, the Sun mining among 
C{ them, muft of neceffity produce a vehe- 
Ct ment heat; fincemany of his rays, which 
cc would otherwife, perhaps, never touch 
" our earth, are hereby reflected to us 5 thus* 
ci if the Sun be on one fide, and the clouds 
tc on the oppofue one, they will be perfect 
ci burning-glaiTe'S. 

u I have fometimes (continues he) ob- 
ct fcrved a kind of hollow clouds, full of 
cx hail and fnow, during the continuance 
Ci of which the heat was extreme; fince by 
iC fuch condenfation they w r ere enabled to 
<c reflect: much more ftrongly. After this 
cc came a fharp cold, and then the cloud s 
<c difcharged their hail in great quantity; 
:< to which fucceeded a moderate warmth. 

" Frozen 

Vegetable Staticks. 39 

" Frozen concave clouds therefore, by their 
" great reflections, produce a vigorous heat, 
" and the fame, when refolved, exceflive 
« cold/* 

Whence we fee that blafts may be occa- 
fioned by the reflections of the clouds, as 
well as by the above mentioned refraction of 
denfe tranfparent vapors. 

July 21. I obferved that at that feafon 
the top of the Sunflower being tender, and 
the flower near beginning to blow, if 
the Sun rife clear, the flower faces towards 
the Eaft ; and the Sun continuing to fhine, 
at noon it faces to the South ; and at fix in 
the evening to the Weft: And this not by 
turning round with the Sun, but by nuta- 
tion; the caufe of which is, that the fide of 
the ftem next the Sun perfpiring molt, it 
fhrinks, and this plant perfpires much. 

I have obferved the fame in the tops of 
Jerufalem-artichokes, and of garden- beanss 
in very hot Sun-fhine. 

Experiment X. 

July 27. I fixed an Apple-branch, m y 3 
feet long, \ inch diameter, full of leaves, 
D 4 and 

40 Vegetable Staticks. 

and lateral {hoots to the tube /, 7 fee t 
long, JL of an inch diameter, {Fig. 3.) I fil- 
led the tube with water, and then immerfed 
the whole branch as far as over the lower 
end of the tube, into the veflel uu full of 

The water fubfided 6 inches the firft two 
hours, (being the firft filling of the fap-vef- 
fels) and 6 inches the following night, 4 
inches the next day ; and 2 + ^ the following 

The third day in the morning I took the 
branch out of the water, and hung it, with 
the tube affixed to it, in the open air; it im- 
bibed this day 27 +~ inches in 12 hours 

This experiment fhews the great power 
of perfpiration; fince, when the branch was 
immerfed in the veflel of water, the 7 feet 
column of water in the tube, above the fur- 
face of the water, could drive very little 
thro' the leaves, till the branch was expofed 
to the open air. 

This alfo proves, that the perfpiring mat- 
ter of trees is rather actuated by warmth, 
and 10 exhaled, than protruded by the force 
of the lap upwards. 


Vegetable Statich. 41 

And this holds true in animals, for the 
perfpiration in them is not always greateft in 
the greateft force of the blood ; but then often 
leaft of all, as in fevers. 

I have fixed many other branches in the 
fame manner to long tubes, without immerf- 
ing them in water ; which tubes, being filled 
with water, I could fee precifely, by the 
defcent of the water in the tube /, how faft 
it perfpired off, and how very little perfpired 
in a rainy day, or when there were no leaves 
on the branches. 

Experiment XI. 

Aug. 17. At 1 1 a : m, I cemented to 
the tube ab (Fig. 4.) 9 feet long, and \ inch 
diameter, an Apple-branch d> 5 feet long, £ 
inch diameter 5 I poured water into the tube, 
\vhich it imbibed plentifully, at the rate of 
3 feet length of the tube in an hour. At 
1 o' clock I cut off the branch at c, 13 inches 
below the glafs tube. To the bottom of 
the remaining ftem I tied a glafs ciftern z y 
covered with ox-gut, to keep any of the 
water which dropped from the ftem cb, from 
evaporating. At the fame time I fet the 


4& Vegetable Staticks. 

branch d r, which I had cut off in a known 
quantity of water, in the veffel x (Fig. 5.). 
The branch in the veffel x imbibed 18 ounces 
of water in 18 hours day and 12 hours night; 
in which time only 6 ounces of water had 
paffed thro' the (tern c by (Fig. 4.) which had 
a column of water 7 feet high, prefling upon 
it all the time. 

This again fhews the great power of per- 
fpiration; to draw thrice as much water, 
in the fame time, through the long (lender 
parts of the branch r, (Fig. 5.) as was preffed 
thro' a larger (lem cb (Fig. 4.) of the fame 
branch; but 13 inches long, with 7 feet 
preffure of water upon it, in the tube a b. 

I tried in the fame manner another Ap- 
ple-branch, which in 8 hours day imbibed 
20 ounces, while only 8 ounces paffed thro' 
the item <rZ>, (Fig. 4.) which had the column 
of water on it. 

The fame I tried with a quince branch, 
which in 4 hours day imbibed 2 ounces'-f-i., 
while but.*, ounce paffed thro' the (lem cb 
(Fig. 4.) which had 9 feet weight of water 
prelfmg on it. 

Xcie, All thefe (under this experiment 
11.) were made the firft day> before the 


Vegetable Staticks. 45 

ftem could be any thing faturate with water, 
or the fap-veflels fhrunk fo as to hinder its 

Experiment XII. 

I cut off from a dwarf Apple-tree e w the 
top of the branch /, (Ffg. 6.) which was an 
inch diameter, and fixed to the ftem /, the 
glafs tube lb: then I poured warer into the 
tube, which the branch would imbibe, at 
fuch a rate as to drink down 2 or 3 pints in 
a day, efpecially if I fucked with my mouth 
at the top of the tube /5, fo as that a few air- 
bubbles were drawn out of the ftem /-, then 
jthe water was imbibed fo faft, that if I im- 
mediately fcrewed on the mercurial gage, 
mryz, the mercury would be drawn up 
to r, 12 inches higher than in the other 

At another time I poured into the tube /, 
fixed to a golded Renate-tree, a quart of 
high rectified fpirit of wine camphorated, 
which quantity the ftem imbibed in 3 hours 
fpace ; this killed one half of the tree : this 
I did to try if I could give a flavour of cam- 
phire to the apples which were in great 


44 Vegetable Statkks. 

plenty on the branch. I could not perceive 

any alteration in the tafte of the apples, tho' 

they hung feveral weeks after; but the fmell 

of the camphire was very ftrong in the ftalks 

of the leaves, and in every part of the dead 


I made the fame experiment on a vine, 
with ftrongly-fcented orange -flower- water; 
the event was the fame, it did not penetrate 
into the grapes, but very fenfibly into the 
wood and ftalks of the leaves. 

I repeated the fame experiment on two 
diftant branches of a large Catharine pear- 
tree, with ftrong decoctions of Saffafrafs, and 
of Elder-flowers, about 30 days before the 
pears were ripe ; but I could not perceive any 
tafte of the decoctions in the pears. 

Tho' in all thefe cafes the fap-veffels of 
the ftem were ftrongly impregnated with a 
good quantity of thefe liquors; yet the capil- 
lary fap-veflels near the fruit were fo fine, 
that they changed the texture of, and aflimi- 
lated to their own fubftance, thofe high-tafted 
and perfumed liquors; in the fame manner 
as grafts and buds change the very different 
fap of the ftock to that of their own fpecifick 


46 Vegetable Staticks. 

it did not rife at all in the tube, tho' the 
top of the ftem was wet: I then filled the 
tube with water, but it paffed freely into the 
veflel x. 

Experiment XV. 

Sept. 10. 2+ jl feet from the ground, I 
cut off the top of a half ftandard Duke Cherry- 
tree againft a wall, and cemented on it the 
neck of a Florence flask f y (Fig. 8.) and 
to that flask neck a narrow tube g, five feet 
long, in order to catch any moifture that 
fhould arife out of the trunk y , but none 
arofe in four hours, except a little vapor that 
was on the flask's neck. 

I then dug up the tree by the roots, and 
fet the root in water, with the glaffes affixed 
to the top of the ftem j after feveral hours 
nothing rofe but a little dew, which hung 
on the infide off, yet it is certain by many 
of the foregoing experiments, that if the 
top and leaves of this tree had been on, 
many ounces of water would in this time 
have palled thro' the trunk, and been eva- 
porated thro' the leaves. 

I have 

Vegetable Statlch. 4? 

I have tried the fame experiment with 
feveral vine branches cut off, and fet in Water 
thus, but no water rofe into/. 

Thefe three laft experiments all (hew, that 
tho' the capillary fap-veffels imbibe moifture 
plentifully; yet they have little power to 
protrude it farther, without the affiftance of 
the perfpiring leaves, which do greatly pro- 
mote its progrefs. 

Experiment XVI. 

In order to try whether any fap rofe in 
the winter, I took in January feveral par- 
cels of Filberd-fuckers, Vine-branches, green 
Jeflamine-branches, Philarea and Laurel- 
branches, with their leaves on them -, and dip- 
ped their tranfverfe cuts in melted cement, to 
prevent any moifture's evaporating thro' the 
wounds ; I tied them in feparate bundles, and 
weighed them. 

The Filberd-fuckers decreafed in 8 days, 
(fome part of which were very wet, but the 
laft 3 or 4 days drying winds) the nth part 
of their whole weight. 

The Vine-cuttings in the fame time the 

rt P art - 



48 Vegetable Statich. 

The JelTamine in the fame time the £ part. 

The Philarea decreafed the \ part in five 

The Laurel the ^part in 5 days, and more. 

Here is a confiderable daily wafte of fap, 
which muft therefore neceffarily be fupplied 
from the root; whence ins plain, that fome 
fap rifes all the winter, to fupply this con- 
tinual wafte, tho' in much lefs quantity than 
in fummer. 

Hence we fee good reafon why the Ilex 
and the Cedar of Libanus (which were graft- 
ed the firft on an Englijh Oak, the other on the 
Larix) were verdant all the winter, notwith- 
standing the Oak and Larix leaves were de- 
cayed and fallen off; for tho', when the win- 
ter came on, there did not fap enough rife 
to maintain the Oak and Larix leaves, yet by 
this prefent experiment we fee, that fome 
fap is continually rifing all the winter ; arid 
by experiment the 5th on the Limon-tree, 
and by feveral other the like experiments, on 
many forts of ever-greens, we find that they 
perfpiring little, live and thrive with little 
nourishment; the Ilex and Cedar might 
well therefore continue green all the win- 
ter, notwithstanding the leaves of the trees 


Vegetable Stattch. 49 

they were grafted on fell off. See the late 
curious and induftrious Mr. Fairchild's ac- 
count of thefe graftings in Mr. Millers 
Gardeners Didi.ionary ; vide Sap. 

Experiment XVII. 

Having by many evident proofs in the 
foregoing experiments feen the great quan- 
tities of liquor that were imbibed and per- 
fpired by trees, I was dcfirous to try if I 
could get any of this perfpiring matter ; 
and in order to it, I took feveral glafs chy- 
mical retorts, b a p ( Fig. 9. ) and put the 
boughs of feveral forts of trees, as they 
were growing with their leaves on, into 
the retorts, flopping up the mouth p of the 
retorts with bladder. By this means I got 
feveral ounces of the perfpiring matter of 
Vines, Fig-trees, Apple-trees, Cherry-trees, 
Apricot and Peach-trees ; Rue, Horfe-radilh, 
Rheubarb, Parfnip, and Cabbage leaves: 
the liquor of all of them was very clear, 
nor could I difcover any different tafte in 
the feveral liquors: But if the retort ftand 
expofed to the hot fun, the liquor will 
tafte of the clodded leaves. Its fpecifick 
gravity was nearly the fame with that of 

E common 

jo Vegetable Staticks. 

common water; nor did I find many air- 
bubbles in it, when placed in the exhaufted 
receiver, which I expected to have found ; 
but when referved in open viols, it ftinks 
fooner than common water; an argument 
that it is not pure water ; but has fome he- 
terogeneous mixtures with it. 

I put alfo a large Sun-flower full-blown, 
and as it was growing, into the head of a 
glafs-flill, and put its roftrum into a bottle, 
by which means there diftilled a good quan- 
tity of liquor into the bottle. It will be 
very eafy in the fame manner to colled: the 
perfpirations of fweet-fcented Flowers, tho* 
the liquor will not long retain its grateful 
odor, but ftink in few days. 

Experiment XVIII. 

In order to find out what ftores of moi- 
flure nature had provided in the earth, 
(againft the dry fummer feafon) that might 
anfwer this great expence of it, which is fo 
neceffary for the produ&ion and fupport of 
vegetables 3 

July$ 1. *7 2 4- l d ug up a cubick foot 
earth, in an alley which was very little 
trampled on; it weighed (after deducing 
the weight of the containing veffel ) 104 



/>. 5<? 


Vegetable Statich. 5 1 

pounds 4 ounces + f. A cubick foot of 
water weighs nearly 62- pounds, which is 
little more than half the fpecifick gravity 
of earth. This was a dry feafon, with a 
mixture of fome few fhowers, fo that the 
grafs-plat adjoining was not burnt up. 

At the fame time I dug up another cubick 
foot of earth, from the bottom of the for- 
mer; it weighed 106 pound 6 ounces -j- 4-. 

I dug up alfo a third cubick foot of earth, 
at the bottom of the two former ; it weighed 
in pounds ~{~-j. 

Thefe three feet depth were a good brick 
earth, next to which was gravel, in which 
at 2 feet depth, viz. 5 feet below the fur- 
face of the earth, the fprings did then run. 

When the firft cubick foot of earth was 
fo dry and dufty, as to be unfit for vegeta- 
tion, I weighed it, and found it had loft 
6 pounds ~j- n ounces, or 184 cubick in- 
ches of water, near -§• part of its bulk. ' 

Some days after, the fecond cubick foot 
being drier than either the firft or third, 
was decreafed in weight 10 pounds. 

The third cubick foot, being very dry 
and dufty, had loft 8 pounds 8 ounces, of 
247 cubick inches, viz. \ part of its 

E 2 Now 

54 Vegetable Staticks. 

In a long dry fcafott, therefore, efpecially 
within the Tropicks, we muft have recourfe 
for fufficienc moifturc (to keep Plants and 
Trees alive) to the moift ftrata of earth, 
which lie next below that in which the 
roots are. Now moift bodies always com- 
municate of their moifturc to more dry 
adjoining bodies; but this flow motion of 
the afcent of moift u re is much accelerated 
by the Sun's heat to confiderable depths in 
the earth, as is probable from the following 
20th Experiment. 

Now 1 80 grains of Dew filling in one 
night, on a circle of a foot diameter, = 
113 fquare inches; thefe 180 grains being 
equally fpread on this furface, its depth 

will be 77 part of an inch = 

r 113x254 

I found the depth of Dew in a winter night 
to be the -^ part of an inch ; ib that, if we 
allow 159 nights for the extent of the fum- 
tner's Dew, it will in that time arife to one 
inch depth. And reckoning the remaining 
206 nights for the extent of the winter's 
Dew, it will produce 2.28 inches depth, 
which makes the Dew of the whole year 
amount to 3.28 inches depth. 

And the quantity which evaporated in a 
ftii ;•..;.. ;:ci's day frqm the fame furface, be- 

Vegetable Statkks. 5 5 

ing 1 ounce + 282 grains, gives ■£$ part of 
an inch depth for evaporation, which is 
four times as much as fell at night. 

I found, by the fame means, the evapo- 
ration of a winter's day to be nearly the 
fame as in a fummer's day 5 for the earth 
being in winter more faturate with mos 
fture, that excels of moifture anfwers to the 
excefs of heat in fummer. 

Nic. Cruquius, N Q 381 of the Philofo- 
phical Tranfadtions, found that 28 inches 
depth evaporated in a whole year from wa- 
ter, /. e. ~z °f an inch each day, at a mean 
rate ; but the earth in a fummer's day evapo- 
rates -|~ of an inch ; fo the evaporation of 
a furface of water, is to the evaporation of 
a furface of earth in fummer, as T j to 7 V . 

The quantity of Rain which falls in a 
year is at a medium 22 inches: The quan- 
tity of the earth's evaporation in a year is 
at leaft 9.15 inches, fince that is the rate, 
at which it evaporates in a fummer 's day : 
From which 9.15 inches, are to be deduc- 
ed 3.39 inches for circulating daily Dew; 
there remain 5.76 inches, which 5.76 inches 
dedudled from the quantity of Rain which 
falls in a year, there remain at leaft 16.24 

E 4 inches 

5 6 Vegetable Staticls. 

inches depth, to replenilh the earth with 
moiilure ior vegetation, and to fupply the 
Springs and Rivers. 

In the cafe of the hop-ground, the eva- 
poration from the hops may be confidered 
only for three months at T £ 7 part of an inch 
each day, which will be T 9 o of an inch ; 
but before we allowed 5.76 inches vapour to 
evaporate from the furface of the ground, 
which added to T % inch, gives 6.66 inches 
which is the utmoft that can be evaporated 
from a furface of hop-ground in a year. So 
that of 22 inches depth of rain, there re- 
main 15.34 inches to fupply fprings; which 
are more or lefs exhausted, according to 
the drinefs or wetnefs of the year. Hence 
we find that 22 inches depth of rain in a 
year is fufficient for all the purpoles of na- 
ture, in fuch flat countries as this about 
tfeddington near Hampton-Court. But in 
the hill countries, as in Lancafiirc, there 
falls 42 inches depth of rain-water; from 
which deducting 6.66 inches for evaporation, 
there remains 35.34 inches depth of water 
for the fprings ; befides great fupplies from 
much more plemiful dews, than fall in plain 
countries: Which vail ftores feem fo abun- 
dantly fufficient to anfwer the great quantity 


Vegetable Statuks. 57 

of water, which is conveyed away, by fprings 
and rivers, from thofe hills, that we need 
not have recourfe, for fupplies, to the great 
Abyfs, whofe furface, at high water, is fur- 
mounted fome hundreds of feet by ordi- 
nary hills, and fome thoufands of feet by 
thofe vaft hills from whence the longeft 
and greateft rivers take their rife. See vol. II. 

A *S7- 

Experiment XX. 

I provided me fix Thermometers, whofe 
items were of different lengths, viz. from 
1 8 inches to 4 feet. I graduated them all by 
one proportional fcale, beginning from the 
freezing point ; which may well be fixed as 
the utmofl boundary of vegetation on the fide 
of cold, where the work of vegetation ceafes, 
the watry vehicle beginning then to condenfe 
and be fixed •, tho' many trees, and fome plants 
as grafs, mofs, &c. do furvive it ; yet they 
do not vegetate at that time. 

The greateft degree of heat, which I at 
firft marked on my Thermometers, was equal 
to that of water, when heated to the great- 
eft degree that I could bear my hand in it, 
without ftirring it about. But finding by 
experience, that plants can endure, with- 

58 Vegetable Staticks. 

out prejudice, a fomething greater heat 
than this, I have pitched upon the heat in 
which melted wax fwimming on hot water 
firft begins to coagulate ; for fince a greater 
heat than this will diflblve the wax, which 
is a vegetable fubftance, this may therefore 
well be fixed as the utmoft boundary of ve- 
getation, on the warm fide ; beyond which 
plants will rather fade than vegetate, fuch 
degree of heat feparating and difperfing, in- 
ftead of congregating and uniting the nu- 
tritive particles. 

This fpace I divided into 100 degrees 
on all the Thermometers, beginning to num- 
ber from the freezing point. Sixty-four of 
thefe degrees are nearly equal to the heat of 
the blood of animals - y which I found by 
the rule given in the Philofophical Tranf- 
a&ions, Vol. II. p. 1. of Mr. Mottes Abridg- 
ment, which is fuppofed to be Sir Ifaac 
Nrwtotii eftimate ; viz. by placing one of 
the Thermometers in water heated to the 
greateft degree that I could bear my hand 
in it ftirring it about : And which I wa s 
further affured of, by placing the ball of my 
Thermometer in the flowing blood of an ex- 
piring Ox. The heat of the blood to that 
of boiling water is as 14.27 to 33. 

. By 

Vegetable Stattcks. 59 

By placing the ball of one of thefe Ther- 
mometers in my bofom, and under an arm- 
fit, I found the external heat of the body 
54 of thefe degrees. The heat of milk, as 
it comes from the Cow, is equal to 55 de- 
grees, which is nearly the fame with that 
for hatching of eggs -, the heat of urine 
58 degrees. The common temperate point 
in thermometers is about 18 degrees. 

The hotteft Sun-fhine in the year 1727 
raifed the fpirit in the Thermometer expofed 
to it, 88 degrees j a heat 24 degrees greater 
than that of the blood of animals : And 
tho' plants endure this, and a confiderably 
greater heat within the Tropicks, for fome 
hours each day, yet the then hanging of the 
leaves of many of them fhews that they 
could not long fubfift under it, were they 
not frequently refreshed by the fucceeding 
evening and night. 

The common noon-tide heat in the Sun 
in July is about 50 degrees : The heat of 
the air in the {hade in July is at a medium 
38 degrees. The May and June heat is from 
17 to 30 degrees: the mod genial heat for 
the generality of plants, in which they flou- 
rish moft, and make the greatefl progrefs in 
their growth. The autumnal and vernal 


60 Vegetable Staticks, 

heat may be reckoned from 10 to 20 de- 
grees : The winter heat from the freezing 
point to 10 degrees. 

The fcorching heat of a hot-bed of horfe- 
dung, when too hot for plants, is equal to 
85 degrees and more; and hereabout is pro- 
bably the heat of blood in high fevers. 

The due healthy heat of a hot-bed of 
horfe-dung, in the fine mold, where the 
roots of thriving Cucumber-plants were, 
in Feb. was equal to 56 degrees, which is 
nearly the bofom heat, and that for hatch- 
ing of eggs. The heat of the air under the 
glais-frame of this hot-bed was equal to 
34 degrees; fo the roots had 26 degrees 
more heat than the plants above ground. 
The heat of the open air was then 17 de- 

It is now grown a common and very rea- 
fonable praclice, to regulate the heat of 
ftoves and green-houfes, by means of Ther- 
mometers hung up in them. And for 
greater accuracy, many have the names of 
fome of the principal exoticks written up- 
on their Tiber mometers^ over-againft the fe- 
veral degrees of hear, which are found by 
experience to be propereft for them. And 
I am informed that many of the moft cu- 

Vegetable Staticks. 6\ 

rious Gardeners about London have agreed 
to make ufe of Thermometers of this fort ; 
which are made by Mr. John Fowler in 
Swithirfs- Alley, near the Royal-Exchange* 
which have the names of the following 
plants, oppofite to their refpeftive moft 
kindly degrees of heat ; which in my Ther- 
mometers anfwer nearly to the following de- 
grees of heat above the freezing point, viz. 
Melon-thiftle 31, Ananas 29, Piamento 26, 
Euphorbium 24, Cereus 2J-, Aloe 19, In- 
dian-fig i6~, Ficoides 14, Oranges 12^ Myr- 
tles 9. 

Mr. Boyle, by placing a Thermometer in 
a cave, which was cut ftrait into the bot- 
tom of a cliff, fronting the Sea, to the depth 
of 130 feet, found the fpirit flood, both in 
winter and fummer, at a fmall divifion above 
temperate; the cave had 80 feet depth 
of earth above it. Boyle's Works, Vol. III. 
p. 54. 

I marked my fix Thermometers numeri- 
cally, 1, 2, 3, 4, 5, 6. The Thermometer 
numb. 1, which was fhorteft, I placed with 
a South afpedt, in the open air; the ball 
of numb. 2, I fet two inches under ground ; 
that of numb. 3, four inches under ground; 
numb. 4, 8 inches; numb. 5,1 6 inches; and 


6 i Vegetable Staticks. 

numb. 6, 24 inches underground. And that 
the heat of the earth, at thefe feveral depths, 
may the more accurately be known, it is 
proper to place near each Thermometer a 
glafs-tube fealed at both ends, of the fame 
length with the ftems of the feveral Ther- 
mometers -, and with tinged fpirit of wine 
in them, to the fame height, as in each 
correfponding Thermometer ; the fcale of 
degrees, of each Thermometer ■, being mark- 
ed on a Aiding ruler, with an index at the 
back of it, pointing to the correfponding 
tube. When at any time an obfervation is 
to be made, by moving the index, to point 
to the top of that fpirit in the tube, an ac- 
curate allowance is hereby made, for the 
very different degrees of heat and cold, on 
the ftems of the Thermometers, at all depths ; 
by which means the fcale of degrees will 
fhew truly the degrees of heat in the balls 
of the Thermometers, and confequently, the 
refpe&ive heats of the earth at the feveral 
depths where they are placed. The ftems 
of thefe Thermometers, which were above 
ground, were fenced from weather and in- 
juries by fquare wooden tubes \ the ground 
they were placed in was a brick earth in 
the middle of my garden. 

Vegetable Staticks. 63 

July 30. I began to keep a regifter of 
their rife and fall. During the following 
month of Augujl, I obferved that when 
the fpirit in the thermometer, numb. 1, 
( which was expofed in the Sun ) was about 
noon rifen to 48 degrees, then the fecond 
Thermometer was 45 degrees, the fifth 33, 
and the fixth 3 1 5 the third and fourth at 
intermediate degrees. The fifth and fixth 
Thermo??ieter kept nearly the fame degree 
of heat both night and day, till towards 
the latter end of the month ; when, as the 
days grew fhorter and cooler, and the nights 
longer and cooler, they then fell to 25 and 
27 degrees. 

Now, fo con fider able a heat of the Sun, 
at two feet depth, under the earth's furface, 
muft needs have a ftrong influence in rail- 
ing the moifture at that and greater depths ; 
whereby a very great and continual wreak 
muft always be afcending, during the warm 
fummer feafon, by night as well as day; for 
the heat at two feet depth is nearly the fame 
night and day, the impulfe of the Sun- 
beams giving the moifture of the earth a 
brifk undulating motion, which watery par- 
ticles, when feparated and rarefied by heat, 
do afcend in the form of vapour : And the 


^4 Vegetable Staticks. 

vigour of warm and confined vapour (fuch 
as is that which is i, 2, or 3 feet deep in 
the earth) muft be very confiderable, fo as 
to penetrate the roots with fome vigour; 
as we may reafonably fuppofe, from the 
vaft force of confined vapour in /Eolipiles, 
in the digefter of bones, and the engine to 
raife water by fire. See. Vol. II. p. 259. 

If plants were not in this manner fup- 
plied with moifture, it were impoflible for 
them to fubfifl under the fcorching heats 
within the Tropicks, where they have no 
rain for many months together: For tho' 
the dews are much greater there, than in 
thefe more Northern climates ; yet doubtlefs, 
where the heat io much exceeds ours, the 
whole quantity evaporated in a day there, 
does as far exceed the quantity that falls 
by night in dew, as the quantity evaporat- 
ed here in a fummer's day, is found to ex- 
ceed the quantiry of dew which falls in the 
night. But the dew, which fidls in a hot 
fummer feafon, cannct poflibly be of any 
benefit to the roots of trees; becaufe it is 
remanded back from the earth by the fol- 
lowing day's heat, before {o fmall a quantity 
of moifture can have foaked to any con- 
fiderable depth. The great benefit there- 

Vegetable Staticks. 6j 

fore of dew, in hot weather, muft be, by 
being plentifully imbibed into vegetables ; 
thereby not only refrefhing them for the 
prefent, but alfo furnifhing them with a 
frefh fupply of moifture towards the great 
expences of the fucceeding day. 

'Tis therefore probable, that the roots of 
trees and plants are thus, by means of the 
Sun's warmth, conftantly irrigated with 
frefh fupplies of moifture; which, by the 
fame means, infinuates itfelf with fome 
vigour into the roots. For, if the moifture 
of the earth were not thus actuated, the roots 
muft then receive all their nourifhment 
merely by imbibing the next adjoining 
moifture from the earth ; and confequently 
the fhell of earth, next the furface of the 
roots, would always be confiderably drier, 
the nearer it is to the root; which I have 
not obferved to be fo. And by Exper. 1 8, 
and 19, the roots would be very hard put to 
it to imbibe fufficient moifture in dry fum- 
mer weather, if it were not thus conveyed 
to them by the penetrating warmth of the 
Sun : Whence by the fame genial heat, in 
conjunction with the attraction of the ca- 
pillary fap-vefTels, it is carried up thro* the 
bodies and branches of vegetables; and 
F thence 

66 Vegetable Staticks. 

thence pa (Ting into the leaves, it is there 
moft vigoroufly acted upon, in thofe thin 
plates, and put into an undulating motion, 
by the Sun's warmth, whereby it is moft 
plentifully thrown off, and perfpired thro' 
their furface ; whence, as foon as it is dif- 
intangled, it mounts with great rapidity in 
the free air. 

But when, towards the latter end of 
Oflober, the vigour of the Sun's influence is 
fo much abated, that the firft Thermometer 
was fallen to 3 degrees above the freezing 
point, the fecond to 10 degrees, the fifth 
to 14 degrees, and the fixth Thermometer to 
16 degrees j then the brisk undulations of 
the moifture of the earth, and alfo of the 
afcending fap, much abating, the leaves faded 
and fell off. 

The greateft degree of cold, in the fol- 
lowing winter, was in the firft 12 days of 
November ; during which time, the fpirit in 
the firft Thermometer was fallen 4 degrees 
below the freezing point, the deepeft Ther- 
mometer 10 degrees, the ice on ponds was 
an inch thick. The Sun's greateft warmth, 
at the winter folftice, in a very ferene, calm, 
frofty-day, was, againft a South afpedl of a 
wall, 19 degrees and in a free open air, but 

11 de- 

Vegetable Staticks. 67 

1 1 degrees above the freezing point. From 
the 10th of January to the 29th of March 
was a very dry feafon ; when the green 
Wheat was generally the fineft that was 
ever remembred. But from the 29th of 
March J 72 5, to the 29th of September fol- 
lowing, it rained more or lefs almoft every 
day, except ten or twelve days about the 
beginning of July, and that whole feafon 
continued fo very cool, that the fpirit in 
the firft Thermometer rofe but to 24 degrees > 
except now and then in a fhort interval of 
Sunfhine ; the fecond only to 20 degrees ; 
the fifth and fixth to 24 and 23 degrees, 
with very little variation: So that during 
this whole fummer, thofe parts of roots which 
were two feet under ground, had three or 
four degrees more warmth than thofe which 
were but two inches under ground : And at 
a medium the general degree of heat thro* 
this whole fummer, both above and under 
ground, was not greater than the heat of 
the middle of the preceding September. 

The year 1725 having been, both in this 
ifland, and in the neighbouring nations, moft 
remarkably wet and cold; and the year 
J723, in the other extreme, as remarkably 
dry, as ha« ever been known ; it may not 
Fa be 

68 Vegetable Statich. 

be improper here to give a fhort account of* 

them, and the influence they had on their 


Mr. Miller, in the account which he 
took of the year 1723, obferved, " That the 
<c winter was mild and dry, except that in 
" February it rained almoft every day, which 
" kept the fpring backward. March, April, 
" May, June, to the middle of July, proved 
" extremely dry, the wind North-eaft moft 
" part of the time. The fruits were for- 
<c ward, and pretty good ; but kitchen-ftuflf, 
<c efpecially Beans and Peas, failed much. 
<c The latter half of July the weather proved 
" very wet, which caufed the fruits to 
C£ grow fo faft, that many of them rotted 
" on the trees; fo that the autumn fruits 
" were not good. There were great plenty 
cc of Melons, very large, but not well tailed. 
" Great plenty of Apples -, many kinds of 
" fruits bloffomed in Augujl, which pro- 
<c duced many fmall Apples and Pears in 
c< October, as alfo Strawberries and Rafp- 
<c berries in great plenty. Wheat was good, 
" little Barley, much of which was very un- 
€C equally ripe, fome not at all, becaufe fown 
<c late, and no timely rain to fetch it up. 
£ There were innumerable Wafps -, how it 

" fared 

Vegetable Staticks. 69 

" fared with the hops this dry year, is men- 
' f tioned under Exper. 9. 

" The following winter, 1724, proved 
" very mild ; the fpring was forward in Ja- 
" nuary, fo that the Snow-drops, Crocus's, 
" Polyanthus's, Hepaticas, and Narcijfuss, 
C{ were in flower. And it was remarkable, 
cc that moft of the Colliflower-plants were 
■•" deftroyed by the mildew, of which there 
u was more, all this winter, than had been 
" known in the memory of man. In Fe- 
cc bruary we had cold fharp weather, which 
" did fome damage to the early crops, and 
" it continued variable till April, fo that 
" much of the early Wall-fruit was cut off: 
ct And again the 6th of May was a very 
<c (harp froft, which much injured tender 
c< plants and fruits. The fummer in general 
fcC was moderately dry, the common fruits 
cc proved pretty good, but late: Melons 
c< and Cucumbers were good for little; 
*' Kitchenrftuff was in great plenty in the 
€c markets/' 

In the very wet and cold year 1725, moft 
things were a full month backwarder than 
ufual. Not half the Wheat in by the 24th 
of Augujl, in the Southern parts of England-. 
very few Melons or Cucumbers, and thofe 

F 3 no£ 

?o Vegetable Staticks. 

not good. The tender Exoticks fared but ill; 
fcarce any grapes, thofe fmall, and of very 
unequal fizes, on the fame bunch, not ripe ; 
Apples and Pears green and infipid ; no fruit 
nor products of the ground good, but crude: 
Pretty good plenty of Wheat, tho' coarfe, 
and long ftraw ; Barley coarfe, but plenty 
of it in the uplands. Beans and Peas mod 
flourifhing and plentiful ; few Wafps or 
other infects, except Flies on hops. Hops 
were very bad thro' the whole kingdom. Mr. 
Aujlin of Canterbury fent me the following 
particular account, how it fared with them 
there \ where they had more than at Farnham, 
and moft other places, viz. 

Cl At mid- April not half the fhoots ap- 
<< peared above ground ; fo that the plant- 
<c ers knew not how to pole them to the 
" beft advantage. This defect of the flioot, 
« c upon opening the hills, was found to be 
" owing to the multitude and variety of 
" vermin that lay preying upon the root; 
< c the increafe of which was imputed to 
< c the long and almoft uninterrupted feries 
< c of dry weather, for three months pafl : 
<c Towards the end of April, many of the 
? c hop-vines were infefted with the Flies. 
* About the 20th of May there was a 

« very 

Vegetable Statich. 71 

u very unequal crop, fome Vines being 
" run feven feet, others not above three or 
" four feet -> fome juft tied to the poles, and 
<c fome not vifible : And this difpropor- 
li tionate inequality in their lize continued 
" through the whole time of their growth. 
u The Flies now appeared upon the leaves 
(< of the forwarded Vines, but not in fuch 
'* numbers here, as they did in moft other 
'* places, About the middle of June y the 
u Flies increafed, yet not fo as to endanger 
* c the crop 5 but in diftant plantations they 
* c were exceedingly multiplied, fo as to 
a fwarm towards the end of the month. 
** June 27th fome fpecks of Fen appeared : 
" From this day to the 9th of July, was 
" very fine dry weather. At this time, 
" when it was faid that the Hops in moft 
u ocher parts of the kingdom looked black 
" and fickly, and feemed pail: recovery, ours 
* f held it out pretty well, in the opinion 
IC of the moft skilful planters. The great 
" leaves were indeed difcoloured, and a lit- 
M tie withered, and the Fen was fomewhat 
" increafed, From the 9th of July to the 
c c 23d the Fen increafed a good deal, but 
< c the Flies and Lice decreafed, it raining 
M daily much : In a week more the Fen, 
F 4 " which 

71 Vegetable Staticks. 

" which feemed to be almoft at a (land, 
u was confiderably increafed, efpecially in 
M thofe grounds where it firft appeared. 
u About the middle of Augtijl, the Vines 
< : had done growing, both in ftem and 
" branch ; and the forwarded began to be 
*' in Hop, the reft in Bloom : The Fen 
" continued fpreading, where it was not 
€t before perceived, and not only the leaves, 
t% but many of die Burs alfo were tainted 
cz with it. About the 20th of Aiigujl, 
u fome of the Hops were infected with the 
" Fen, and whole branches corrupted by it. 
u Half the Plantations had hitherto pretty 
" well efcaped, and from this time the Fen 
" increafed but little: But feveral days vio- 
<c lent wind and rain, in the following 
cc week, fo difordered them, that many of 
(i them began to dwindle, and at laft came 
c: to nothing 5 and of thofe that then re. 
11 mained in bloom, fome never turned to 
11 Hops; and of the reft which did, many 
" of them were fo fmall, that they very 
iC little exceeded the bignefs of a good 
lc thriving Bur. We did not begin to pick 
" till the eighth of September, which was 
" eighteen days later than we began the 
' f year before. The crop was little above 

" two 

Vegetable Statich. 7$ 

« two hundred on an acre round, and not 
" good." The beft Hops fold this year 
at Way -Hill Fair for fixteen pounds the 

The almoft uninterrupted wetnefs and 
coldnefs of the year 1725, very much af- 
fe&ed the produce of the Vines the enfu- 
ing year ; and we have fufficient proof from 
the obfervations that the four or five laft 
years afford us, that the moifture or drinefs 
of the preceding year has a confiderable in- 
fluence on the productions of the Vine the 
following year. Thus in the year 1722, 
there was a dry feafon, from the beginning 
of Augujl thro' the following autumn and 
winter, and the next fummer there was 
good plenty of Grapes. The year 1723 was 
a remarkably dry year, and in the following 
year 1724, ihere was an unufual plenty of 
Grapes. The year 1724 was moderately 
dry, and the following fpring the Vines 
produced a fufficient quantity of bunches; 
but by reafon of the wetnefs and coldnefs 
of the year T725, they proved abortive, and 
produced hardly any Grapes. This very 
wet year had an ill effect, not only upon its 
own productions, but alfo on thofe of the 
following year: For notwithftanding there 


74 Vegetable Staticks. 

was a kindly fpring, and blooming feafon, in 
the year 1726, yet there were few bunches 
produced, except here and there in fome 
very dry foils. This many Gardeners fore- 
faw early, when, upon pruning of the Vines, 
they obferved the bearing (hoots to be crude 
and immature j which was the reafon why 
they were not fruitful. The firft crop thus 
failing in many places, the Vines produced 
a fecond, which had not time to come to 
maturity before the cold weather came on. 

Mr. Miller fent me the following ac-r 
count of the long and fevere winter in the 
year 1728; and of the effedl it had on the 
plants and trees in this and the neighbour- 
ing countries, 'viz. 

" The autumn began with cold North 
H and Eaft winds, and early in November 
" the nights were generally frofty ; tho' the 
" froft did not enter the ground deeper than 
" the fucceeding days thaw'd. But towards 
" the end of November the winds blew ex- 
" tremely cold from the North, which was 
c< fucceeded by a great fnow, which fell in 
M fuch quantities in one night, as to break 
<c off large arms and tops of many ever-green 
" trees, on which it lodged. 

« After 

Vegetable Stathks. 75 

* c After the fnow was down, it began to 
<c freeze again, the wind continuing to 
« blow from the North ; the days were 
" dark and cloudy for fome time, bucaf- 
" terwards it cleared up, and the Sun ap* 
cc peared almoft every day, which melted 
■" the fnow where expofed to it, whereby 
P the froft penetrated the deeper into the 
ic ground. It was pbfervable, that during 
" thefe clear days, a great mift or vapour 
" appeared in the evenings, floating near 
" the furface of the ground, till the cold 
P* of the night came on, when it was fud- 
" denly condenfed and difappeared ; the 
P nights now began to be extreme fharp. 
<c The fpirit in the Thermometer was 18 de- 
" grees below the freezing point, (as mark- 
" ed upon Mr. Fowler's Thermometers) and 
* c it was at this time that vaft quantities of 
" Lauriiftimis'sy Phyllyreas, Alaternuss^ Rofe- 
" wary, and other tender plants began to 
P fufferj efpecially fuch as were trimm'd 
" up to naked items, or had been clipp'd 
" late in the fummer. At this time alfo 
P there were great numbers of trees diC- 
" barked, fome of which were of a confi- 
M derable bulk ; particularly two Weft-India 
U Plane Trees^ in the Phyfick Garden at 

P Chelfea, 

7 6 Vegetable Statich. 

<< Chelfea, which are near forty feet high. 
<c and a fathom in circumference, were dif- 
" barked almoft from the bottom to the 
" top, on the weft fide of the trees. And 
" in a nurfery belonging to Mr. Francis 
il Hurji, great numbers of large Pear-trees 
< c were all of them disbarked on the Weft or 
« South-Weft fides of 'em. And in feveral 
« other places I obferved the like accident, 
" and foun^ it was conftantly on the fame 
M fide of the trees. 

<( About the middle of December the 
" froft abated of its intenfenefs, and feemed 
<< to be at a Hand, till the 23d of the month, 
« c when the wind blew extreme fharp and 
«' cold from the Eaft, and the froft continued 
" very hard to the 28th day, at which time 
lt it began to abate again, and feemed to be 
H going off, the wind changing to rhe Scuih ; 
" but it did not continue long id this point, 
" before it changed to the Eaft again, and 
" the froft returned, tho' not fo violent as 
<•' before. 

iC Thus the weather continued for the 
cc moft part frofty, till me middle of March, 
" with a fevy intervals of mild weather, 
li which brought forward fome of the early 
u flowers i but the cold returning, foon de- 

a ftroyed 

Vegetable Staticks* 77 

ct ftroyed them ; io that thofe plants which 
" ufually flower in January and February, 
ci did not this year appear till the latter end 
" of March) or the beginning of April \ as 
" the Crocus's, Hepaticas 6 Perfian Iris's, 
" Black Hellebores, Polyanthus's, Mezereons, 
u and many others. 

u The Colliflower - plants which were 
ct planted out during the intervals between 
" the froft, were moft of them deftroyed, 
" or fo much pinched, as to lofe the great- 
" eft part of their leaves 5 whereas thofe 
" which had been planted out in Ottober 
cc efcaped very well. The early Beans and 
" Peas were moft of them deftroyed ; and 
" great quantities of timber and fruit-trees, 
" which had been lately removed, were quite 
" killed. 

" The lofs was very great in moft cu- 
" rious collections of plants ; there being 
" a great deftru&ion made of many trees, 
" fhrubs, and plants, which had endured 
" the open air many years, wichout being 
" the leaft hurt by cold; as the Granadilla 
" or Paffion-flowe?\ Arbutus or Straw- 
l£ berry Tree, Cork Tree, with moft of the 
<c Aromatick Plants, as Rofemary, Laven- 
€i ' der, Stcechas, Sage, Maftick, Mar urn, 

" and 

7% Vegetable Staticks. 

H and many others, which were deftroyed 
u to the ground, and were by many people 
" pulled up and thrown away ; but in warm 
'■• dry foils, where they were fuffered to re- 
< c main undifturbed, many of them broke 
u out from the root again, tho' it was very 
u late in the fummer before they fhewed any 
cc figns of recovery. 

u The plants in the confervatories fuffered 
<c very much by being fo long (hut up clofe ; 
e< for the days being for the moft part cloudy, 
* c and the wind blowing very ftiarp, the 
<c windows of the green-houfes could not be 
<c with fafety opened, which occafioned a 
<c noxious damp in the houfes, whereby the 
c£ plants became fickly, languifhed and de- 
€< cayed foon after. 

" Nor was the froft more fevere with us 
" than in other parts of Europe, but on 
" the contrary in comparifon favourable -, 
l< for in the Southern parts of France the 
<£ Olives, Myrtles , Ci/luss, and other trees 
" and fhrubs, which grow there almoft 
c< fpontaneoufly, were deftroyed ; and in the 
<c Northern parts of France, as about Paris, 
" &c. the buds of many kinds of fruit-trees 
u were deftroyed, although clofed, fo that 
c< many of them never opened, but decayed 

" and 

Vegetable Statuks. 79 

*< and perifhed; and the Fig-trees which 
" were expofed to the open air, were alfo 
ic deftroyed. 

" In Holland the Pines, Firs, and other 
" hardy refinous trees, were moft of them 
cl killed, altho' many of them are natives 
<c of the Alps, and other mountainous cold 
" countries ; but this I apprehend to be ow- 
" ing to the lownefs of their fituation and 
" foil, whereby their roots eafily ran down 
" into the water, which is more injurious to 
11 thefe trees than froft. 

<c But it was obferved, that the trees and 
" fhrubs which are natives of Virginia and 
a Carolina, efcaped well in Holland-, when 
" almoft all thofe which were b/ought from 
" Italy, Spain, or the South parts of France, 
< c were intirely deftroyed. Which will greatly 
<c inhance the value of the former trees, ef- 
" pecially fuch of them as are either proper 
" for ufe or beauty. 

" In Germany the winter was fo fevere as 
* to deftroy almoft all their plants and flowers, 
<c which were not either removed into the 
" green - houfes, or protedled by coverings 
u from the froft, as I was informed by letters 
u from thence. 

« And 

8o Vegetable Statich. 

" And in Scotland the froft and fnow did 
" great damage, fome of the particulars of 
€i which I fhall tranfcribe from a letter, 
<l which I received from a gentleman living 
" near Edinburgh who is a curious ob- 
u ferver. 

" About the 20th of November, he fay9, 
cc they had much fnow, which lay ten days, 
<c and then went off very pleafantly without 
" rain 5 and from that time till the middle 
" of December, we had very good winter 
ct weather, when a great fnow fell, which 
" was attended with a ftorm from the North- 
<c eaft -, which fnow lay very thick upon the 
" ground till the 12th day of January, du- 
" ring which time there was a very intenfe 
" froft: After which the cold abated, and 
cc the fnow went off gradually •, and about 
" the end of January, I obferved in my 
cc green- houfe the flowers and young fhoots 
" of the Orange and other exotick trees did 
" begin to appear, and all of them began to 
" prepare for vegetation. In the open ground 
" we had Spring Cyclamens, Primrofes, Win- 
" ter Aconites, Snowdrops, Hellebores, Poly- 
" anthuss, Glajlenbury Thorn, Winter Hya- 
c cinths, and Mezereons in flowv \ 



Vegetable Staticks. 81 

u But before I proceed to give a farther 
cc account of the weather, I fhail offer you 
<c my thoughts upon the reafon of this ve- 
cc gecation fo early, whilft the cold was fo 
" intenfe with you. Firft, it is to be obferved, 
" that our ftorms of fnow at that feafon 
" came on before the froft had entered the 
" ground; fo that the fnow kept the ground 
" warm and fecure from the froft, which 
" only crufted the top of the fnow : Du- 
" ring this feafon the wind blew from the 
(c Eafr, which coming off the fea, (from 
< c which we are but eight miles diftant) was 
< c not attended with fo much cold as if it 
" had blown over the land, which was 
cc covered with fnow, where there is no 
cc fea for two hundred miles. Till the fifth 
li of February we enjoyed this weather \ at 
<c which time we had a violent fnow with 
<c a ftorm from the South-w 7 eft, and the 
<c froft having entered the ground before it 
" fell, checked our early flowers from ap- 
" pearing : During this fnow, which con- 
" tinued moft part of February, we had a 
" great deal of fun-mine, which contributed 
■ very much to our early crops of Cu- 
" cumbers and Melons ; but during the nights 
" it froze very hard, which deftroyed great 
G " numbers 

8 1 Vegetable Statieks. 

" numbers of plants that were not fhel- 
" tered. 

" Every thing was now at a ftand ; the 
iC Apricot and Peac h bloflbms continued tur- 
" gid; but not being opened, they fuffered 
" very little; the Laurujlinuss fuffered 
u extremely by this laft fevere feafon, efpe- 
" cially where the (how had been melted from 
cl their roots. 

" This fnow went off with a violent 

<c South-well wind, which was very bleak 

<£ and cold ; and where the fun had no ac- 

" cefs, the fnow lay till the 12th of March y 

" at which time we had for fix days very 

M mild weather, which occafioned our put- 

if ting abroad our Carnatiojis, thereby we 

* loft moft of them. The wind continued 

" cold, varying from the South-weft to the 

c< North-weft, and fometimes North-eaft> 

" and upon the 23d day it was very cold, 

« the wind at North-weft and by North; 

" in the evening the fun was clouded, and 

<•' the wind abated, the Mercurv in the Ba- 

¥ rometer fell at night; at two o' clock the 

<f next morning a violent hurricane at 

" North-eaft brought a fnow in many 

" places, 6, 10, and 12 feet deep, with a 

" moft piercing cold; the fnow continued 

•' to 

Vegetable Staticks. 83 

«« to fall till ten o' clock in the morning, 
" when the wind chopped about to the 
u North-weft with incredible fiercenefs, 
« and extreme cold. Now it was that in- 
" numerable fheep and other cattle were 
<c loft in the mountains of fnow; and many 
cc poor people going that morning to 
<c look after their cattle, the remembrance 
" of which is terrible, were equally fuf- 
" ferers with them, being buried in the 
cc fnow. 

" The Apricots and Peaches v/hich were 
<c now in bloffom upon warm walls, were 
u all deftroyed, and not only the bloflbms, 
" but the trees alfo, their bark burfting 
»■ off." 

I have often obferved from thefe Ther- 
mometers, when that kind of hovering lam- 
bent fog arifes, ( either mornings or even- 
ings) which frequently betokens fair wea- 
ther, that the air which in the preceding 
day was much warmer, has upon the ab- 
fence of the fun become many degrees 
cooler than the furface of the earth ; which 
being near 1500 times denfer than the air, 
cannot be fo foon affected with the alter- 
nates of hot and cold ; whence 'tis pro- 
bable, that thole vapours which are raifed 

G 2 by 

84 Vegetable Staticks. 

by the warmth of the earth, are by the 
cooler air foon condenfed into a vifible 
form. And I have obferved the fame dif- 
ference between the coolnefs of the air, and 
the warmth of water in a pond, by putting 
my Thermometer, which hung all night in' 
the open air in fummer time, into the water, 
juft before the rifing of the fun, when the 
like wreak or fog was rifing on the furface of 
the water. 


Experiment l s> whereby to find out the force 
with which trees imbibe moijlure. 

HAving in the firft chapter fecn many 
proofs of the great quantities of li- 
quor imbibed and perfpired by vegetables, 
I propofe in this, to inquire with what force 
they do imbibe moifture. 

Tho' vegetables (which are inanimate) 
have not an engine, which, by its alternate 
dilatations and contractions, does in animals 
forcibly drive the blood through the arte- 
ries and veins; yet has nature wonderfully 


Vegetable Staticks. 85 

contrived other means, moft powerfully to 
raife and keep in motion the fap, as will in 
fome meafure appear by the experiments in 
this and the following chapter. 

I (hall begin with an experiment upon roots, 
which nature has providently taken care to 
cover with a very fine thick ftrainer ; that 
nothing (hall be admitted into them, but what 
can readily be carried off by perfpiration, vege- 
tables having no other provifion for difcharg- 
ing their recrement. 

Experiment XXI. 

Auguft 13. in the very dry year 1723, 
I dug down 2 + ~ feet deep to the root 
of a thriving baking Pear-tree, and laid 
bare a root ~ inch diameter n (Fig. 10.) I 
cut off the end of the root at i 3 and put 
the remaining ftump i n into the glafs tube 
dr, which was 1 inch diameter, and 8 inches 
long, cementing it faft at r; the lower part 
of the tube d z was 1 8 inches long, and \ 
inch diameter in bore. 

Then I turned the lower end of the tube 

z uppermoft, and filled it full of water, and 

then immediately immerfedthe fmall end z 

into the ciftern of mercury x ; taking away 

G 3 my 

86 Vegetable Staticks. 

my finger, which flopped up the end of the 
tube z. 

The root imbibed the water with fo much 
vigour, that in 6 minutes time the mercury 
was railed up the tube d z as high as z y viz. 
8 inches. 

The next morning at 8 o' clock, the mer- 
cury was fallen to 2 inches height, and z 
inches of the end of the root i were yet im- 
meried in water. As the root imbibed the 
water, innumerable air-bubbles hTued out at 
/, which occupied the upper part of the tube 
at r 3 as the water left it. 

Experiment XXII. 

The eleventh experiment mews, with what 
great force branches imbibe water, where a 
branch with leaves imbibed much more than 
a column of 7 feet height of water could in 
the fame time drive through 13 inches length 
of the biggeft part of its item. And in the 
following experiments wc fhali find a farther 
proof of their ftrpng imbibing power. 

MiiX 25, I cut off a branch of a young 
thriving yi/^/t'-Zra? b, (Fig. 11.) about 3 feet 
long, with lateral branches ; the diameter of 
ti.e tranfverfe cut /, where it was cut off, 


Vegetable Staticks. 87 

was \ of an inch : The great end of this branch 
I put into the cylindrical glafs e r, which 
was an inch diameter within, and eight inches 

I then cemented faft the joint r, firfl fold- 
ing a ftrap of fheeps-skin round the Hem, fo 
as to make it fit well to the tube at r ; then 
I cemented faft the joint with a mixture of 
Bees-wax and Turpentine melted together in 
fuch a proportion, as to make a very ftiff 
clammy pafte when cold, and over the cement 
I folded feveral times wet bladders, binding 
it firm with packthread. 

At the lower end of the large tube e was 
cemented, on a lefier tube z e, {■ inch dia- 
meter in bore, and 1 8 inches long : The fub- 
ftance of this tube ought to be full f of an 
inch thick, elfe it will too eafily break in 
making this experiment 

Thefe two tubes were cemented together 
at e y firft with common hard brick-duft ce- 
ment to keep the tubes firm to each other ; 
but this hard cement would, both by being 
long moift, and by the different dilatations 
and contractions of the glafs and cement, 
feparate from the glafs in hot weather, fo 
as to let in air ; to prevent which incon- 
venience, I further fecured the joint with 

G 4 the 

8 8 Vegetable Statkks. 

the cement of Bees-wax and Turpentine, 
binding a wet bladder over all. If the hard 
cement be made of powder'd chalk inftead 
of brick-duft, it is more binding, and is not 
fo apt to be loofened by water. 

When the branch was thus fixed, I turned 
it downwards, and the glafs tube upwards, 
and then filled both tubes full of water ; 
upon which I immediately applied the end 
of my finger to clofe up the end of the 
fmall tube, and immerfed it as faftaslcould 
into the glafs ciflern x, which was full of 
mercury and water. 

When the branch was now uppermoft, 
and placed as in this figure, then the lower 
end of the branch was immerfed 6 inches in 
water, viz. from r to i. 

Which water was imbibed by the branch, 
at its tranfverfe cut /; and as the water af- 
cended up the fap-veffels of the branch, fo 
the mercury afcended up the tube e z from 
the cittern x ; fo as in half an hour's time 
the mercury was rifen 5 inches and | high 
up to z. 

And this height of the mercury did in 
feme meafure ihew the force with which the 
fa p was imbibed, tho' not near the whole 
force; for while the water was imbibing, 


Vegetable Staticks. 89 

the tranfverfe cut of the branch was covered 
with innumerable little hemifpheres of air, 
and many air-bubbles iffued out of the fap- 
veffels, which air did in part fill the tube e r, 
as the water was drawn out of it 5 fo that 
the height of the mercury could only be 
proportionable to the excefs of the quantity 
of water drawn off, above the quantity of 
air which iffued out of the wood. 

And if the quantity of air, which iffued 
from the wood into the tube, had been equal 
to the quantity of water imbibed, then the 
mercury would not rife at all •> becaufe there 
would be no room for it in the tube. 

But if 9 parts in 1 2 of the water be im- 
bibed by the branch, and in the mean time 
but three fuch parts of air iffueinto the tube, 
then the mercury muft needs rife near 6 
inches, and fo proportionably in different 

I obferved in this, and moft of the follow- 
ing experiments of this fort, that the mer- 
cury rofe higheft, when the fun was very 
clear and warm; and towards evening it 
would fubfide 3 or 4 inches, and rife again 
the next day as it grew warm, but feldom 
to the fame height it did at firft. For I have 
always found the fap-veffels grow every day, 


90 Vegetable Staticks. 

after cutting, lefs pervious, not only for water, 
but alio for the fap of the vine, which never 
paries to and fro fo freely thro' the tranfverfe 
cut, after it has been cut 3 or 4 days, as at 
firft ; probably, becaufe the cut capillary 
veffels are fhrunk, the veficles alfo, and in- 
terfaces between them, being faturate and 
dilated with extravafated fap, much more 
than they are in a natural ftate. 

If I cut an inch or two off the lower 
part of the ftem, which has been much fa- 
turated by Handing in water, then the branch 
will imbibe water again afrefh ; tho' not alto- 
gether fo freely, as when the branch was firft 
cut off the tree. 

I repeated the fame experiment as this 
2 2d, upon a great variety of branches of 
feveral fizes and of different kinds of trees, 
fome of the principal of which are as fol- 
low, viz. 

Experiment XXIII. 

July 6th and 8th, I repeated the fame 
experiment with feveral green fhoots of the 
Vine y of this year's growth, each of them 
full two yards long. 

The mercury rofe much more leifurely in 
thefe experiments, than with the Apple-tree 

branch -, 

Vegetable Statkks. 91 

branch ; the more the fun was upon it, the 
fafter and higher the mercury rofe, but the 
Vine-branches could not draw it above 4 
inches the firft day, and 2 inches the third 

And as the fun fet, the mercury fometimes 
fubfided wholly, and would rife again the 
next day, as the fun came on the Vine- 

And I obfei'ved, that where fome of thefe 
Vine-branches were fix'd on the North-fide 
of the large trunk of a Pear-tree, the mer- 
cury then rofe mod in the evening about 6 o* 
clock, as the fun came on the Vine-branch. 

Experiment XXIV. 

Auguft 9, at 10 ante Merid. (very hot 
funftiine) I fixed in the fame manner as Ex. 
22. a Non-pareil branch, which had 20 Apples 
on it ; it was 2 feet high, with lateral branches, 
its tranfverfe cut £ inch diameter : It imme- 
diately began to raife the mercury moft vigo- 
roufly, fo as in 7 minutes it was got up to 
z 12 inches high. 

Mercury being 13 | times fpecifically 
heavier than water, it may eafily be eftima- 
ted to what height the feveral branches in 


$> i Vegetable Staticks. 

thefe experiments would raife water; for 
if any branch can raife mercury 12 inches, 
it will raife water 13 feet 8 inches: A fur- 
ther allowance being alfo made for the per- 
pendicular height of the water in the tubes, 
between r and z the top of the column of 
mercury ; for that column of water is lifted 
np by the mercury, be it more or lefs. 

At the fame time, I tried a Golden Re- 
nate branch 6 feet long ; the mercury rofe 
but 4 inches, it rifing higher or lower in 
branches nearly of the fame fize and of the 
fame kind of tree, according as the air iffued 
thro' the ftem, more or lefs freely. In the 
preceding experiment on the Nonpareil branch, 
I had fucked a little with my mouth at the 
fmall end of the tube, to ge£ fome air-bub- 
bles out of it, before I immerfed it in the 
mercury $ (but thefe air-bubbles are beft got 
out by a fmall wire run to and fro in the 
tube) and this faction made air-bubbles arife 
out of the tranfverfe cut of the branch : but 
tho* the quantity of thofe air-bubbles thus 
fucked out, was but fmall ; yet in this and 
many other "experiments, I found, that after 
fuch faction, the water was imbibed by the 
branch much more greedily, and in much 
greater quantity, than the bulk of the air was, 


Vegetable Stathks, <?j 

which was fucked our. Probably therefore, 
thefe air-bubbles, when in the fap-veffels, do 
flop the free afcent of the water, as is the cafe 
of little portions of air got between the water 
in capillary glafs tubes. 

When the mercury is raifed to its great- 
eft height, by precedent fudtion with the 
mouth, (which height it reaches fometimes 
in 7 minutes, fometimes in half an hour or 
an hour) then from that time it begins to 
fall, and continues fo to do, till it is fallen 
5 or 6 inches, the height the branch would 
have drawn it to, without fucking with the 

But when, in a very warm day, the mer- 
cury is drawn up 5 or 6 inches, (without 
precedent fudtion with the mouth) then it 
will ufually hold up to that height for feve- 
ral hours, viz. during the vigorous warmth 
of the fun; becaufe the fun is all that time 
ftrongly exhaling moifture from the branch 
thro 1 the leaves - y on which account it muft 
therefore imbibe water the more greedily, 
as is evident by many experiments in the firft 

When a branch is fixed to a glafs tube 
fet in mercury, and the mercury fubfides at 
night, it will not rife the next morning, 


9 4 J' e get able Staticks. 

(as the warmth of the fun increafes upon it) 
unlefs you fill the tube fir ft full of water: 
For if half or I of the large tube cr be full 
of air, that air will be rarefied by the fun ; 
which rarefaction will deprefs the water in 
the tube, and confequently the mercury can- 
not rife. 

But where little water is imbibed the firft 
day, (as in the cafe of the green fhoots of the 
Vine, Exper. XXIII.) then the mercury will 
rife the fecond and third day, as the warmth 
of the fun comes on, without refilling the 
little water that was imbibed. 

Exper iment XXV. 

In order to make the like experiment on 
larger branches, (when I expected the mer- 
cury would have rifen much higher than in 
fmall ones) I caufed glafilrs to be blown 
of the fh ape of this here defcribed (Fig. 12.) 
of feveral dimenfions at r, from two to 
five inches diameter, with a proportionably 
large cavity c; the ftem z as near i_ inch 
diameter as could be, the length of the ftem 
16 inches. 

I cemented one of thefe glafs veffels to 
a large fmooth barked thriving branch of an 


9 6 Vegetable Statkks. 

the glafs tube z r, to the remaining branch 
i r> and then filling the tube with water, fet 
its lower end in the mercury x - y fo that now 
the branch was placed with its top i down- 
wards in the water, in the Aqueomercurial 


It imbibed the water with fuch ftrength, as 
to raife the mercury with an almoft equable 
progreffion 1 1 + 4 inches by 3 o' clock (the 
fun mining then very warm) 3 at which time 
the water in the tube r i being all imbibed, 
fo that the end i of the branch was out of the 
water, then the air-bubbles paffing more freely 
down to /, and no water being imbibed, the 
mercury fubfided 2 or 3 inches in an hour. 

At a quarter pad 4 o' clock, I refilled the 
gage with water ; upon which the mercury 
rofe afrefh from the ciftern, viz. 6 inches 
the firft ^ of an hour, and in an hour more 
the mercury reached the fame height as be- 
fore, viz. 1 1 + \ inches. And in an hour 
and \ more, it rofe -J. inch more than at firft ; 
but in half an hour after this it began gently 
to fubfide; viz. becaufe the fun declining 
and fetting, the perfpiration of the leaves 
decreafed, and confequently the imbibing of 
the water at i abated, for the end i was then 
an inch in water, 


Vegetable Staticks. 97 

July 3 lft, it raining all this day, the mer- 
cury rofe but 3 inches, which height it 
flood at all the next night. Aitguft ift, fair 
fun-mine ; this day the mercury rofe to 8 in- 
ches : This mews again the influence of the 
fun, in raifing the mercury. 

This Experiment proves that branches will 
ftrongly imbibe from the fmall end immer- 
fed in water to the great end; as well as 
from the great end immerfed in water to 
the fmall end; and of this we mall have 
further proof in the fourth chapter. 

Experiment XXVII. 

In order to try whether branches would 
imbibe with the like force with the bark 
off, I took two branches, which I call M 
and N\ I fixed M in the fame manner as 
the branch in the foregoing Experiment, 
with its top downwards, but firft I took off 
all the bark from i to r. Then fix'dl in the / 

fame manner the branch N> but with its 
great end downwards, having alfo taken off 
all the bark from / to r- both the branches 
drew the mercury up to z, 8 inches; fo 
they imbibed with equal ftrength at either 
end, and that without bark. 

H Expe- 

Vegetable Statichi 99 

tube : And if thefe wounds (thro* which the 
air always iflued plentifully) were well co- 
vered with fheeps gut, bound over with 
packthread, it would in a good meafure 
prevent the inconvenience : But I always 
found that my experiments of this kind 
fucceeded beft, when that part of the branch 
which was to enter the tube r i 9 was clear 
of all knots or wounds j for when there 
were no knots, the liquor paiTed moil free- 
ly, and lefs air iffued out. 

The fame day I fixed in the fame man- 
ner a gage to an Apricot-tree ; it raifed the 
mercury three inches; and tho' all the water 
was foon imbibed, yet the mercury role 
every day an inch, for many days, and fub- 
fided at night j fo that the branch muft 
daily imbibe thus much air, and remit it at 

Experiment XXX. 

We have a further proof of the influence 
of the leaves in raifing the fap in this fol- 
lowing Experiment. 

Auguft 6th, I cut off a large Ruffet 
Pippin a, (Fig. 15.) with a ftalk 1 ~f \ inch 
long, and 12 adjoining leaves g growing to 

H 2 I ce- 

ioo Vegetable Staticks. 

I cemented the flalk faft into the upper 
end of the tube d, which tube was 6 inches 
long, and \ inch diameter - y as the ftalk im- 
bibed the water, it raifed the mercury to z> 
four inches high. 

I fixed another Apple of the fame fizeand 
tree in the fame manner, but firft pulled 
off the leaves ; it raifed the mercury but I 
Inch. I fixed in the fame manner a like 
bearing twig with 12 leaves on it. but no 
apple; it raifed the mercury 3 inches. 

I then took a like bearing twig, without 
either leaves or apple; it raifed the mercury 

I inch 

o a twig with an apple and leaves raif- 
ed the mercury 4 inches, one with leaves 
only 3 inches, one with an apple without 
leaves 1 inch. 

A Quince which had two leaves, juft at 
the twig's infertion into it, raifed the mer- 
cury 2 + \ inches, and held it up a confi- 
derable time. 

A fprig of Mint fix'd in the fame manner, 
raifed the mercury 3 -j- \ inch, equal to 4 
feet 5 inches height of water. 


Vegetable Staticks. 101 

Experiment XXXI. 

I tried alfo the imbibing force of a great 
variety of trees, by fixing Aqueo-mercuriai 
gages to branches of them cut off, as in Ex- 
periment 22. 

The Pear, Quince, Cherry, Walnut, Peach, 
Apricot, Plum, Black-thorn, White-thorn, 
Goofeberry, Water-elder, Sycamore, raifed 
the mercury from 6 to 3 inches high : Thofe 
which imbibed water moft freely, in the Ex- 
periments of the firft chapter, raifed the 
mercury higheft in thefe Experiments, ex- 
cept the Horfe-Chefnut, which, though it 
imbibed water moft freely, yet raifed the 
mercury but one inch, becaufe the air paf- 
fed very fait through its fap-veffels into the 


The following raifed the mercury but 1 
or 2 inches, viz. the Elm, Oak, Horfe- 
Chefnut, Filberd, Fig, Mulberry, Willow, 
Sallow, Ofier, Am, Lynden, Currans. 

The Ever-greens, and following trees and 
plants, did not raife it at all ; the Laurel, 
Rofemary, Lauruftinus, Phyllyrea, Fuz, Rue, 
Berberry, Jeffamine, Cucumber-branch, Pum- 
kin, Jerufalem Artichoke. 

H 3 Expe- 

102 Vegetable Staticks. 


We have a further proof of the great 
force with which vegetables imbibe moi- 
fture, in the following Experiment, viz. I 
filled near full with Peas and Water, the 
iron Pot ( Fig. 37.) and laid on the Peas a 
leaden cover, between which and the fides 
of the Pot, there was room for the air which 
came from the Peas to pafs freely. I then 
laid 184 pounds weight on them, which (as 
the Peas dilated by imbibing the water) 
they lifted up. The dilatation of the Peas 
is always equal to the quantity of Water 
they imbibe : For if a few Peas be put in- 
to a VeiTel, and that Veffel be filled full of 
water, tho' the Peas dilate to near double 
their natural fize, yet the water will not 
flow over the veiTel, or at moll very incon- 
fiderably, on account of the expanfion of 
little air-bubbles, which are hTuing from the 

Being defiious to try whether they would 
raife a much greater weight, by means of a 
lever with weights at the end of it, I com- 
preffed feveral frefh parcels of Peas in the 
fame Pot, with a force equal to 1600, 800, 
and 400 pounds> in which Experiments, tho' 


Vegetable Statich. i o ; 

the Peas dilated, yet they did not raife the 
lever, becaufe what they increafed in bulk 
was, by the great incumbent weight, prefled 
into the interfaces of the Peas, which they 
adequately filled up, being thereby formed 
into pretty regular Dodecahedrons. 

We fee in this Experiment the vaft force 
with which fwelling Peas expand ; and 'tis 
doubtlefs a confiderable part of the fame 
force which is exerted, not only in pufhing 
the Plume upwards into the air, but alfo in 
enabling the firft (hooting radicle of the Pea, 
and all its fubfequent tender Fibres, to pene- 
trate and moot into the earth. 

Experiment XXXIII. 

We fee, in the Experiments of this chap- 
ter, many inftances of the great efficacy of 
attraction; that univerfal principle which 
is fo operative in all the very different 
works of nature; and is moft eminently fo 
in vegetables, all whofe minuteft parts are 
curioufly ranged in fuch order, as is bcfl 
adapted, by their united force, to attract pro- 
per nourishment. 

And we mall find in the following Ex- 
periment, that the diflevered particles of 
vegetables, and of other bodies, have a 

H 4 ftrong 

1 04 Vegetable Staticks. 

flrong attractive power when they lie con- 

That the panicles of wood are fpecifical- 
ly heavier than water, ( and can therefore 
flrongly attract it ) is evident, becaufe feveral 
forts of wood fink immediately; others 
(even cork) when their fnterftfceS are well 
foaked, and filled with water: As Dr. Def- 
aguliers informed me, he found a cork 
which had been fealed up in a tube with 
water for 4 years, to be then fpecifically 
heavier than water; others (as the Peruvian 
Bark) fink when very finely pulverized, be- 
caufe all their cavities which made them 
ivvim, are thereby deltroyed. 

In order to try the imbibing power of 
common wood allies, I filled a elafs tube 
c r i> 3 feet long, and | of an inch diameter, 
(Fig. 16.) with well dried and fiftcd wood 
aihc?, prefiing them clofe with a rammer; I 
tied a piece of linen over the end of the 
tube at /, to keep the allies from falling out ; 
I then cemented the tube c h(l at r to the 
Aqueo-mercurial gage r z ; and when I had 
filled the £a<:e full of water, I immerfed it 
iti the ciftern of mercury x ; the 1 to the 
upper end of the tube c 7 ac o a I fcrewed on 
the mercurial gzge a t. 


Vegetable Stattcks. 105 

The afhes, as they imbibed the water, drew 
the mercury up 3 or 4 inches in a few hours 
towards z -, but the three following days it 
role but 1 inch, •£• inch, and •£, and fo lefs 
«nd lefs, fo that in 5 or 6 days it ceafed 
rifing : The higheft it rofe was 7 inches, 
which was equal to raifing water 8 feet 

This had very little effect on the mer- 
cury in the gage a b, unlefs it were, that it 
would rife a little, viz. an inch or little 
more in the gage at a, as it were by the fuc- 
tion of the afhes, to fupply fome of the air- 
bubbles which are drawn out at i. 

But when I feparated the tube c from 
the gage r z, and fet the end i in water, 
then the moifture (being not reftrained as 
before) rofe fafter.and higher in the afhes 
c 0, and deprefled the mercury at a, fo as 
to be 3 inches lower than in the leg b y by 
driving the air upwards, which was inter- 
mixed with the afhes. 

I filled another tube 8 feet long, and ~ 
inch diameter, with red lead 5 and affixed it 
in the place, of c 10 the gages a b, r z, 
The mercury rofe gradually 8 inches to z. 

In both thefe Experiments, the end i was 
covered with innumerable air-bubbles, many 


1 06 Vegetable Staticks. 

of which continually patted off, and were 
fucceeded by others, as at the tranfverfe ctm 
in the Experiments of this chapter. And as 
there, fo in thefe, the quantity of air-bub- 
bles decreafed every day, fo as at laft to have* 
very few : The part i immerfed in the wa- 
ter, being become fo fatarate therewith, as 
to leave no room for air to pafs. 

After 20 days I picked the minium' out 
of the tube, and found the water had rifen 
3 feet 7 inches, and would no doubt have 
rifen higher, if it had not been clogged 
by the mercury in the gage z. For which 
reafon the moifture rofe but 20 inches in 
the afhes, where it would otherwife have 
rifen 30 or 40 inches. 

And as Sir Ifaac Newton (in his Op- 
tkks, query 31.) obferves, lt The water rifes 
" up to this height, by the aftion only of 
" thofe particles of the afhes which are up- 
" on the furface of the elevated water ; the 
" particles which are within the water, at- 
" tradting or repelling it as much down- 
,f wards as upwards ; and therefore the ac- 
" tidn of the particles is very flrong : But 
" the particles of the allies being not fo" 
" denfe and clofe together as thofe of glafs, 
H their adion is not fo flrong as that of 

! c glafs* 

Vegetable Statkks. 107 

4< glafs, which keeps quick-filver fufpended 
" to the height of 60 or 70 inches, and 
cc therefore ads with a force, which would 
" keep water fufpended to the height of 
" above 60 feet. 

" By the fame principle, a fponge fucks 
<c in water; and the glands in the bodies of 
" animals, according to their feveral natures 
te and difpoiitions, fuck in various juices 
" from the blood." 

And by the fame principle it is, that we 
fee, in the preceding Experiments, plants im- 
bibe moifture fo vigoroufly up their fine ca- 
pillary veflets; which moifture, as it is car* 
ried off in perfpiration, ( by the action of 
warmth) thereby gives the fap-veflels liber- 
ty to be almoft continually attracting of 
frefli fupplies ; which they could not do, if 
they were full faturate with moifture : For 
without perfpiration the fap muft neceflarily 
ftagnate, notwithstanding the fap-veffels are 
fo curioufly adapted by their exceeding fine- 
nefs, to raife the fap to great heights, in a 
reciprocal proportion to their very minute 

C H A 1\ 

io8 Vegetable Statich. 


Experiments, jhewing the force of the jap 
in the Vine in the bleeding feafon. 

HAVING in the firft chapter (hewn 
many inflances of the great quanti- 
ties imbibed and perfpired by trees, and in 
the fecond chapter feen the force with 
which they do imbibe moiflure - y I propofe 
next to give an account of thofe Experi- 
ments, which will prove with what great 
force the fap of the Vine is pufhed forth, in 
the bleeding feafon. 

Experiment XXXIV. 

March 30th at 3 p. m. I cut off a Vine 
on a weflern afpe<ft, within feven inches of 
the ground ; the remaining flump c (Fig. 17.) 
had no lateral branches : It was 4 or 5 years 
old, and -| inch diameter. I fix'd to the top 
of the flump, by means of the brafs collar 
h y the glafs tube b f\ feven feet long, and 
-J inch diameter ; I fecured the joint b with 
fliff cement made of melted Bees- wax and 
Turpentine, and bound it fafl over with fe- 
veral folds of wet bladder and packthread : 

I then 

Vegetable Staticks. lop 

I then fcrewed a fecond tube/g to the firft, 
and then a third g a y to 25 feet height. 

The ftem not bleeding into the tube, I 
filled the tube two feet high with water; 
the water was imbibed by the ftem within 
3 inches of the bottom, by 8 o' clock thac 
evening. In the night it rained a fmall 
Ihower. The next morning at 6 and ~, the 
water was rifen three inches above what it 
was fallen to laft night at eight o' clock. 
The thermometer which hung in my porch 
was 1 1 degrees above the freezing point. 
March 3 1 from 6 and \ a, m. to id p. m. 
the fap rofe 8 -j- \ inches. April ift, at 6 
a. m. T'hermofneter 3 degrees above the 
freezing point, and a white hoar froft, the 
fap rofe from ten o' clock laft night 3 + \ 
inches more ; and fo continued riling daily 
till it was above 21 feet high, and would 
very probably have rifen higher, if the joint 
b had not feveral times leaked: After flop- 
ping of which it would rife fometimes at 
the rate of an inch in 3 minutes, fo as to 
rife 10 feet or more in a day. In the chief 
bleeding feafon it would continue rifing 
night and day ; but much more in the day 
than night, and moft of all in the greateft 
heat of the day ; and what little finking it 


1 1 o Vegetable Staticks. 

had of 2 or 3 inches was always after fun- 
fet; which I fufpecl was principally occa- 
fioned by the fhrinking and contraction of 
the cement at b, as it grew cool. 

When the fori fhined hot upon the Vine, 
there was always a continued feries of air- 
bubbles, conftantly afcending from the ftem 
thro' the fap in the tube, in fo great plenty 
as to make a large froth on the top of the 
fap, which mews the great quantity of air 
which is drawn in thro" the roots and ftem. 

From this Experiment we find a confide- 
rable energy in the root to pufh up fap in 
the bleeding feafon. 

This put me upon trying, whether I 
could find any proof of fuch an energy, 
when the bleeding feafon was over. In or- 
der to which, 

Experiment XXXV. 

July 4th, at noon, I cut off within 3 in- 
ches of the ground, another Vine on a 
fouth afpecl, and fixed to it a tube 7 feet 
high, as in the foregoing Experiment: I 
filled the tube with water, which was im- 
bibed by the root the firft day, at the rate 
of a foot in an hour, but the next day much 
more (lowly ; yet it was continually finking, 


Vegetable St Micks. i 1 1 

fe that at noon day I could not fee it fo 
much as ftationary. 

Yet by Experiment the 3d, on the Vine 
in the garden pot, it is plain, that a very 
confiderable quantity of fap was daily pref- 
fing thro' this ftem, to fupply the perfpira- 
tion of the leaves, before I cut the Vine off. 
And if this great quantity were carried up by 
pulfion or trufion, it muft needs have rifen 
out of the ftem into the tube. 

Now, fince this flow of fap ceafesat once, 
as foon as the Vine was cut off the ftem, 
the principal caufe of its rife muft at the 
fame time be taken away, viz. the great 
perfpiration of the leaves. 

For tho' it is plain by many Experiments, 
that the fap enters the fap-veflels of plants 
with much vigour, and is probably carried 
up to great heights in thofe veflels, by the 
vigorous undulations of the fun's warmth, 
which may reciprocally caufe vibrations in 
the veficles and fap-veflels, and thereby make 
them dilate and contract a little ; yet it feems 
as plain, (from many Experiments, as parti- 
cularly Exper. 13, 14, 15, and Exper. 43. 
where, tho' we are allured that a great quan- 
tity of water pafled by the notch cut 2 or 3 
feet above the end of the ftem 5 yet was the 


! 1 1 Vegetable Statkks. 

notch very dry, becaufe the attraction of the 
perfpiring leaves was much greater than the 
force of trufion from the column of water: 
From thefe Experiments, I fay, it feems 
evident) that the capillary fap-vefiels, out of 
the bleeding feafon, have little power to pro- 
trude fap in any plenty beyond their ori- 
fices ; but as any fap is evaporated off, they 
can by their ftrong attraction ( affifted by 
the genial warmth of the fun) fupply the 
great quantities of fap drawn off by perfpi- 

Experiment XXXVI. 

April 6th, at 9. a. m. rain the evening be- 
fore, I cut off a Vine on a Southern afpecl, 
at a, (Fig. 18.) two feet nine inches from 
the ground ; the remaining ftem a b had 
no lateral branches ; it was \ inch diameter ; 
I fixed on it the mercurial gage ay. At 1 1 
a. m. the mercury was rifen to z, 15 inches 
higher than the leg x y being pufhed down 
at x, by the force of the fap which came 
out of the ftem at a. 

At /[.p.m. it was funk an inch in the leg zy. 

April 7th at 8 a. ;;;. rifen very little, a 
fog : at 1 1 a. 777 . 'tis 17 inches high, and the 
fog gone. 


Vegetable Statich. 1 1 j 

April ioth, at 7 a. #;. mercury 18 inches 
high; I then added more mercury, fo as to 
make the furface z 23 inches higher than x; 
the fip retreated very little into the ftem, 
upon this additional weight, which fhews 
with what an abfolute force it advances: at 
noon it was funk one inch. 

April 1 ith, at 7 a. m. 24 -p | inches high, 
fun-mine: at 7 p. m> 18 inches high. 

April 14th, at 7 a. m. 20+1 inches high, 
at 9 a.m. 22 ~f"a> fine warm fun-mine ; here 
we fee that the warm morning fun gives a 
frefti vigour to the fap. At 1 1 a. m. the fame 
day i6~-f-~, the great perfpiration of the Hem 
makes it fink. 

April 1 6th at 6 a. m. 19 -j- 4 rain. At 4 
p. m. 13 inches. The fap (in the foregoing 
experiment, numb. 34.) rifen this day fince 
noon 2 inches, while this funk by the perfpi- 
ration of the ftem ; which there was little 
room for, in the very fhort ftem of the other. 
April 17th, at 1 1 a. m. 24 + \ i ncrl high, 
rain and warm; at yp. m. 29 + ~, finewarm 
rainy weather, which made the fap rife all 
day, there being little perfpiration by reafon 
of the rain. 

April 1 8th, at 7 a. m. 32 -J- \ inches high, 
and would have rifen higher, if there had 

I been 

1 1 4. Vegetable Staticks. 

been more mercury in the gage; it being all 
forced into the leg y z. From this time to 
May 5th, the force gradually decreafed. 

The greateft height of the mercury being 
32 -f- i inches; the force of the fap was 
then equal to 36 feet 5 + -j inches height 
of water. 

Here the force of the riling fap in the 
morning is plainly owing to the energy of 
the root and ftem. In another like mercurial 
gage, (fixed near the bottom of a Vine, which 
run 20 feet high) the mercury was raifed by 
the force of the fap 38 inches equal to 43 
feet -f- 3 inches + ~ height of water. 

Which force is near five times greater than 
the force of the blood in the great crural ar- 
tery of a Horfe ; fevtn times greater than 
the force of the blood in the like artery of 
a Dog; and eight times greater than the 
blood's force in the fame artery of a fallow 
Doe: Which different forces I found by 
tying thofe feveral animals down alive upon 
their backs ; and then laying open the great 
left crural artery, where it firft enters the 
thigh, I fixed to it (by means of two brafs 
pipes, which run one into the other) a glafs 
tube of above ten feet long, and i- of an 
inch diameter in bore: In which tube the 


Vegetable StaUcks. 1 i 5 

blood of one Horfe rofe eight feet three 
inches, and the blood of another Horfe eight 
feet nine inches. The blood of a little 
Dog fix feet and half high : In a large 
Spaniel feven feet high. The blood of 
the fallow Doe mounted five feet feven 

Experiment XXXVII. 

April 4th, I fixed three mercurial gages, 
(Fig. 19.) A, B, C, to a Vine, on a South- 
eaft afpecl, which was 50 feet long, from 
the root to the end ru. The top of the wall 
was 1 1 -jf | feet high ; from i to k, 8 feet 5 
from k to e, 6 feet + i. ; from e to A, 1 foot 
10 inches ; from e to 0, 7 feet ; from to B, 
5 + 4 feet; from to C, 22 feet 9 inches; 
from to u, 32 feet 9 inches. 

The branches to which A and C were fixed, 
were thriving moots two years old, but the 
branch B was much older. 

When I firft fixed them, the mercury was 
pufhed by the force of the fap, in- all the gages 
down the legs 4, 5, 13, fo as to rife nine 
inches higher in the other legs. 

The next morning at 7 a. m. the mercury 
in A was pufhed 14 -f- \ inches high, in B 
12 -f-i, in Cj3 -p-i. 

I 2 The 

i ! 6 Vegetable Statich. 

The grcateft height to which they puttied 
the fap feverally, was ^2 1 inches, £26 inches, 
C 26 inches. 

The mercury conftantly fubfided by the 
retreat of the fap about 9 or 10 in the morn- 
ing, when the fun grew hot; but in a very 
moift foggy morning the fap was later before 
it retreated, viz. till noon, or fome time after 
the fog was gone. 

About 4 or 5 o' clock in the afternoon, 
when the fun went off the Vine, the fap be- 
gan to pufli afrefh into the gages, fo as to 
make the mercury rife in the open legs ; but 
it always rofe faftefl from fun-rife till 9 or 
10 in the morning. 

The fap in Z? (the oldefl flem) play'd the 
mod freely to and fro, and was therefore 
fooneft affected with the changes from hot to 
cool , or from wet to dry, and vice verfd. 

And April 10, toward the end of the 
bleeding feafon, B began firft to fuck up the 
mercury from 6 to 5, fo as to be 4 inches 
higher in that leg than the other. But 
April 24, after a night's rain, B puihed the 
mercury 4 inches up the other leg; A did not 
begin to fuck till April 29, viz. 9 days after 
B > C did not begin to fuck till May 3, viz. 
13 days after B> and 4 days after A\ May 5, 


Vegetable Statich. 1 1 7 

at 7 a. ?n. A pufhed 1 inch, Ci+Ij but to- 
wards noon they all three fucked. 

I have frequently obferved the fame dif- 
ference in other Vines, where the like gages 
have been fixed at the fame time, to old and 
young branches of the fame Vine, viz, the 
oldefl began firft to fuck. 

In this experiment we fee the great force 
of the fap, at 44 feet 3 inches diftance from 
the root, equal to the force of a column of 
water 30 feet 11 inches ~j~l high. 

From this experiment we fee too, that 
this force is nor from the root only, but 
muft alfo proceed from fome power in the 
ftem and branches : For the branch B was 
much fooner influenced by changes from 
warm to cool, or dry to wer, and vice verfa % 
than the other two branches A or C -, and 
B was in an imbibing flare, 9 days before 
A y which was all that time in a ftate of 
pufhingfap; and C pufhed 13 days after B 
had ceafed pufhing, and was in an imbibing 

Which imbibing ftate Vines and Applet 
trees continue in, all the fummer, in every 
branch, as I have found by fixing the like, 
gages to the, m in July. 

I 3 Expe- 

1 1 8 Vegetable Staticls. 

Experiment XXXVIII. 

March io, at the beginning of the bleed- 
ing feafon, (which is many days fooner or 
later, according to the coldnefs or warmth, 
inoifture or drinefs of the feafon) I then cut 
off a branch of a vine bfcg at b, (Fig. 20.) 
which was 3 or 4 years old, and cemented 
faft on it a brafs-collar, with a fcrew in it; 
to that I fcrewed another brafs collar, which 
was cemented faft to the glafs tube z y 7 feet 
long and - inch diam. (which I find to 
be the propereft diam.) to that I fcrewed 
ethers, to 38 feet height. Thefe tubes were 
fattened and fecured in long wcoden tubes, 
3 inches fquare, one fide of which was a 
door opening upon hinges ; the ufe of thofe 
wooden tubes was to preferve the glafs tubes 
from being broke by the freezing of the fap 
in them in the night. But when the danger 
of hard frofts was pretty well over, as at the 
beginning of April, then I ufually nVd the 
glaffes without the wooden tubes, fattening 
them to fcaffold poles, or two long ironfpikes 
drove into the wall. 

Before I proceed to give an account of 
the rife and fall of the fap in the tubes, I 


Vegetable Staticks. i 1 9 

will firft defcribe the manner of cementing 
on the brafs collar b, to the ftem of the 
Vine, in which I have been often difappointed, 
and have met with difficulties ; it mud there- 
fore be done with great care. 

Where I defign to cut the ftem, I firft 
pick off all the rough ftringy bark carefully 
with my nails to avoid making any wound 
thro' the green inner bark 5 then I cut ojk^ 
the branch at /, (Fig. 21.) and immediately 
draw over the ftem a piece of dried fheeps- 
gut, which I tie faft, as near the end of the 
ftem as I can, fo that no fap can get by it, 
the fap being confined in the gut if: Then 
I wipe the ftem at i very dry with a warm 
cloth, and tie round the ftem a ftiff paper 
funnel x i> binding it faft at x to the ftem , 
and pinning clofe the folds of the paper from 
x to i : Then I Aide the brafs collar r ever 
the gut, and immediately pour into the pa- 
per funnel melted chalk cement, and then 
fet the brafs collar into it ; which collar is 
warmed, and dipped before in the cement, 
that it may the better now adhere : When 
the cement is cold, I pull away the gut, and 
fcrew on the glafs tubes. 

Buc finding fome inconvenience in this 

hot cement, (becaufe its heat kills the fap- 

I 4 vefTels 

\ 20 Vegetable Staticks. 

vefTels near the bark, as is evident by their 
being difcoloured) I have fince made ufe of 
the cold cement of Bees-wax and Turpentine, 
binding it faft over with wet bladder and pack- 
thread, as in Exper. 34. 

Inftead of brafs-collars, which fcrewed 
into each other, I often (efpecially with the 
Syphons in Exper. 36, and 37.) made life 
^f two brafs collars, which were turned a 
little tapering, fo that one entered and exactly 
fitted the other. 

This joining of the two collars was ef- 
fectually fecured from leaking, by firft 
anointing them with a foft cement ; and 
they were fecured from being disjoined, by 
the force of the afcending fap, by twilling 
packthread round the protuberant knobs on 
the fides of the collars. When I would 
feparate the collars, I found it neceflary 
(except in hot fun-fliine) to melt the foft 
cement by applying hot irons on the out- 
fide of the collars. 

It is needful to made all the cemented 
joints from the fun with loofe folds of pa- 
per, elfe its heat will often melt them, and 
fo dilate the cement, as to make it be drove 
forcibly up the tube., which defeats the ex- 


Vegetable Staticks. ! 1 1 

The Vines to which the tubes in this ex- 
periment were fixed, were 20 feet high from 
the roots to their top; and the glafs tubes 
fixed at feveral heights b from the ground, 
from 6 to 2 feet. 

The fap would rife in the tube the firft 
day, according to the different vigour of the 
bleeding ftate of the Vine, either 1, 2, 5, 
12, 15, or 25 feet; but when ic had got 
to its greateft height for that day, if it was 
in the morning, it would conftantly begin 
to fubfide towards noon. 

If the weather was very cool about the 
middle of the day, it would fubfide only 
from 11 or 12 to 2 in the afternoon; but 
if it were very hot weather, the fap would 
begin to fubfide at 9 or 10 oV clock, and 
continue fubfiding till 4, 5, or 6 in the even- 
ing, and from that time it would continue 
ftationary for an hour or two ; after which 
it would begin to rife a little, but not 
much in the night, nor till after the fun 
was up in the morning, at which time ic 
rofe fafteft. 

The frefher the cut of the Vine was, and 
the warmer the weather, the more the fap 
would rife, and fubfide in a day, us 4 or 6 


121 Vegetable Statich. 

But if it were 5 or 6 days fince the Vine 
was cut, it would rife or fubfide but little ; 
the fap-vefTels at the tranfverfe cue being 
faturate and contracted. 

But if I cut off a joint or two off the 
Hem, and new fixed the tube, the fap would 
then rife and fubfide vigoroufly. 

Moifture and warmth made the fap mod 

If the beginning or middle of the bleed- 
ing feafon, being very kindly, had made the 
motion of the fap vigorous, that vigour would 
immediately be greatly abated by coldeafterly 

If in the morning, while the fap is in a 
rifmg ftate, there was a cold wind with a 
mixture of fun-fhine and cloud ; when the 
fun was clouded, the fap would immediately 
viiibly fubfide, at the rate of an inch in a 
minute for feveral inches, if the fun con- 
tinued fo long clouded: But as foon as the 
fun-beams broke out again, the fap would 
immediately return to its then rifing ftate, 
juft as any liquor in a thermometer rifes and 
falls with the alternacies of heat and cold 5 
whence 'tis probable, that the plentiful rife 
of the fap in the Vine in the bleeding feafon, 
is effected in the fame manner, 


Vegetable Statkks. 123 

When three tubes were fixed at the fame 
time to Vines on an eaftern, a fouthern, and 
a weftern afpedt, round my porch, the fap 
would begin to rife in the morning firft in 
the eaftern tube, next in the fouthern, and 
laft in the weftern tube : And towards noon it 
would accordingly begin to fubfide, firft in 
the eaftern tube, next in the fouthern, and 
laft in the weftern tube. 

Where two branches arofc from the 
fame old weftern trunk, 15 inches from 
the ground; and one of thefe branches 
was fpread on a fouthern, and the other 
on a weftern afpedt ; and glafs tubes were 
at the fame time fixed to each of them 5 
the fap would in the morning, as the fun 
came on, rife firft in the fouthern, then in 
the weftern tube; and would begin to fub- 
fide, firft in the fouthern, then in the weftern 

Rain and warmth, after cold and dry, 
w r ou!d make the fap rife all the next day, 
without fubfiding, tho' ic would rife then 
flowed about noon; becaufe in this cafe 
the quantity imbibed by the root, and 
raifed from it, exceeded the quantity per- 


H4 Vegetable Statich. 

The fap begins to rife fooner in the morn- 
ing in cool weather, than after hot days; 
the reafon of which may be, becaufe in 
hot weather much being evaporated, it is not 
fo foon fupplied by the roots as in cool wea- 
ther, when lefs is evaporated. 

In a prime bleeding feafon I fix'd a tube 
25 feet long to a thriving branch two years 
old, and two feet from the ground, where 
it was cut off; the fap flowed fo briskly, 
as in two hours to flow over the top of the 
tube, which was feven feet above the top of 
the Vine ; and doubtlefs would have rifen 
higher, if I had been prepared to lengthen 
the tube. 

When at the diftance of four or five days, 
tubes were affixed to two different branches, 
which came from the fame ftem, the fap 
would rife higheft in that which was laft 
fixed; yet if in the fixing the fecond tube 
there was much fap loft, the fap would fub- 
fide in the firft tube; but they would not 
afterwards have their fap in equilibrio; i. e. 
the furface of the fap in each was at very 
unequal heights ; the reafon of which is, be- 
caufe of the difficulty with which the fap 
paffes thro* the almoft faturate and contracled 
capillaries of the firfl-cut ftem, 


Vegetable Stattch. i x 5 

In very hot weather many air-bubbles would 
rife, fo as to make a froth an inch deep, oil 
the top of the fap in the tube. 

I fix'd a fmall air-pump to the top of a long 
tube, which had 12 feet height of fap in it 5 
when I pumped, great plenty of bubbles arofe* 
tho* the fap did not rife, but fall a little, after 
I had done pumping. 

In Experiment 34. (where a tube was 
fixed to a very {hort ftump of a Vine, with- 
out any lateral branches) we find the fap 
rofe all day, and fafteft of all in the greateft 
heat of the day : But by many obfervations 
under the 37th and this 38th Experiments, 
we find the fap in the tubes conftantly fub- 
fided as the warmth came on towards the 
middle of the day, and fafteft in the greateft 
heat of the day. Whence .we may reafon- 
ably conclude, (confidering the great perfpi- 
rations of trees, fhewn in the firft chapter) 
that the fall of the fap in thefe fap-gages, 
in the middle of the day, efpecially in the 
warmer days, is owing to the then greater 
perfpiration of the branches, which perfpi- 
ration decreafes, as the heat decreafes towards 
evening, and probably wholly ceafes when 
the dews fall. 


\l6 Vegetable Staticks. 

But when towards the latter end of Jlprtl 
the fpring advances, and many young fhoots 
are come forth, and the furface of the Vine 
is greatly increafed and inlarged by the ex- 
panfion of feveral leaves, whereby the per- 
fpiration is much increafed, and the fap more 
plentifully exhaufted, it then ceafes to flow 
in a vifible manner, till the return of the 
following fpring. * 

And as in the Vine, To is the cafe the 
fame in all the bleeding trees, which ceafe 
bleeding as foon as the young leaves begin 
to expand enough to perfpire plentifully, and 
to draw off the redundant fap. Thus the 
bark of Oaks, and many other trees, mod: 
eafily feparates, while it is lubricated with 
plenty of fap : But as foon as the leaves 
expand fufficiently to perfpire off plenty of 
fap, the bark will then no longer run, (as 
they term it) but adheres rnoft firmly to 
the wood. 

Experiment XXXIX. 

Jn order to try if I could perceive the flem 
of the Vine dilate and contract with heat or 
cold, wet or dry, a bleeding or not bleeding 
feaibn, fome time in February y I hVd to the 


Vegetable Statich. 117 

ftem of a Vine an inftrument in fuch a man- 
ner, that if the ftem had dilated or contracted 
but the one hundredth part of an inch, it 
would have made the end of the inftrument 
(which was a piece of ftrong brafs-wire, 18 
inches long) rife or fall very fenfibly about 
one tenth of an inch ; but I could not per- 
ceive the inftrument to move, either by heat 
or cold, a bleeding or not bleeding feafon. 
Yet whenever it rained, the ftem dilated fo as 
to raife the end of the inftrument or lever 
-^ of an inch; and when the ftem was dry, 
it fubfided as much. 

This Experiment fhews, that the fap (even 
in the bleeding feafon) is confined in its proper 
veflels, and that it does not confufedly per- 
vade every interftice of the ftem, as the rain 
does, which entering at the peripiring pores* 
foaks into the interftices, and tfeereby dilates 
the ftem. 


iiB Vegetable Stattch. 

Experiments, Jhcwing the ready lateral mo- 
tion oj the fap y and confequently- the late- 
ral communication of the fap-vejjels. The 
free fajjage of it fro?n the f mall branches 
towards the ft em y as well as from the ft em 
to the branches. With an account of fome 
Experiments, relating to the circulation or 
non-circulation of the jap. 

Experiment XL. 

IN order to find whether there was any 
lateral communication of the fap and fap- 
veiTels, as there is of the blood in animals, 
by means of the ramifications, and lateral 
communications of their vefTels ; 

Augufl 15th, I took a young Oak-branch 
Y inches diameter, at its tranfverfe cut, fix 
feet high, and full of leaves. Seven inches 
from the bottom, I cut a large gap to the 
pith, an inch long, and of an equal depth 
the whole length ; and four inches above 
that, on the oppofite fide, I cut fuch ano- 
ther gaps I let the great end of the ftem 
in water : It imbibed and perfpired in two 
nights and two days thirteen ounces, while 


Vegetable Statkks. 129 

another like Oak-branch, fomewhat bigger 
than this, but with no notch cat in its ftem, 
imbibed 25 ounces of water. 

At the fame time I tried the like experi- 
ment with a Duke-cherry-branch 5 it imbibed 
and penpired 23 ounces in 9 hours the fxrft 
day, and the next day 15 ounces. 

At the fame time I took another Duke- 
cherry '-branch, and cut 4 fuch fquare gaps 
to the pith, 4 inches above each other; the 
i& North, 2d Eajl, 3d South, /phWeft: It 
had a long (lender ftem, 4 feet length, with- 
out any branches, only at the very top ; yet 
it imbibed in 7 hours day 9 ounces, and in 
two days and two nights 24 ounces. 

We fee in thefe experiments a moil free 
lateral comuunication of the fap and fap-vef- 
fels, thefe great quantities of liquor having 
paffed laterally by the gaps ; for by Experiment 
13, 14, 15, (on cylinders of wood) little 
evaporated at the gaps. 

And in order to try whether it would not 
be the fame in branches as they grew on trees, 
I cut 2 fuch oppofite gaps in a 'Duke-cherry- 
branch, 3 inches diftant from each other: The 
leaves of this branch continued green, within 
8 or 1 o days, as long as the leaves on the other 
branches of the fame tree. 

K The 

i}o Vegetable Staticks. 

The fame day, viz* Aug. 15th, I cut two 
fuch oppofite gaps four inches diftant, in an 
horizontal young thriving Oak-branch -, it was 
one inch diameter, eighteen days after many 
of the leaves begun to turn yellow, which 
none of the leaves of other boughs did 

The fame day I cut off the bark for one 
inch length, quite round a like branch of the 
fame Oak; eighteen days after the leaves 
were as green as any on the fame tree ; but 
the leaves fell off this and the foregoing branch 
early in the winter ; yet continued on all the 
reft of the boughs of the tree (except the top 
ones) all the winter. 

The fame day I cut four fuch gaps, two 
inches wide, and nine inches diftant from 
each other, in the upright arm of a Golden- 
renate - tree -> the diameter of the branch 
was 2 -f-i inch, the gaps faced the four 
cardinal points of the compafs; the apples 
and leaves on this branch flourifhed as 
well as thofe on other branches of the fame 

Here again we fee the very free lateral 
paffage of the fap, where the direft paflage 
is feveral times intercepted. See Vol II. p. 



Vegetable Staticks. 1 3 1 

Experiment XLI. 

Aug. 13th, at noon I took a large branch 
of an Apple-tree, (Fig. 22.) and cemented 
up the tranfverfe cut, at the great end x 9 and 
tied a wet bladder over it : I then cut off the 
main top branch at b ; where it was -| inch 
diameter, and fet it thus inverted into the 
bottle of water b. 

In three days and two nights it imbibed 
and perfpired four pounds two ounces ~j- - 
of water, and the leaves continued green ; the 
leaves of a bough cut off the fame tree at 
the fame time with this, and not fet in 
water, had been withered forty hours be- 
fore. This, as well as the great quantities 
imbibed and perfpired, mews, that the wa- 
ter was drawn from b moft freely to e, f y 
g, b, and from thence down their refpeclive 
branches, and fo perfpired off by the leaves. 

This experiment may ferve to explain 
the reafon, why the branch b, (Fig. 23.) 
which grows out of the root c x y thrives 
very well, notwithftanding the root c x is 
here fuppofed to be cut off at c y and to, 
be out of the ground : For by many expe- 
riments in the firft and fecond chapters, it 
K 2 is 

ip Vegetable Statkks. 

is evident, that the branch b attradts fap 
at x with great force: And by this pre- 
fent experiment, 'tis as evident, that fap 
will be drawn as freely downwards from 
the tree to x, as from c to x, in cafe the 
end c of the root were in the ground ; 
whence 'tis no wonder, that the branch b 
thrives well, tho' there be no circulation of 
the fap. 

This Experiment 41, and Experiment 26, 
do alfo fhew the reafon why, where three 
trees ( Fig. 24. ) are inarched, and thereby 
incorporated at x and z, the middle tree 
will then grow, tho' it be cut off from its 
roots, or the root be dug out of the ground, 
and fufpended in the air; viz. becaufe the 
middle tree b attracts nourifliment ftrongly 
at x and z, from the adjoining trees a c y 
in the fame manner as we fee the inverted 
boughs imbibed water in thefe Exper. 26, 
and 41. 

And from the fame reafon it is that 
Elders, Sallows, Willows, Briars, Vines, 
and mod Shrubs, will grow in an inverted 
ftate, w T idi their tops downwards in the 

Exp e- 

Vegetable Staticks. 133 

Experiment XLII. 

July 27th, I repeated Monfieur Peraulfs 
Experiment ; viz. I took Duke-cherry, Ap- 
ple and Curran- boughs, with two branches 
each, one of which a c (Fig. 25.) I immer- 
fed in the large veilel of water e d y the 
other branch hanging in the open air: I 
hung on a rail, at the fame time, other 
branches of the fame forts, which were then 
cut off. After three days, thofe on the rails 
were very much withered and dead, but the 
branches b were very green ; in eight days 
the branch b of the Duke-cherry was much 
withered : but the Curram and Apple-branch 
b did not fade till the eleventh day: Whence 
'tis plain, by the quantities that muftbeper- 
fpired in eleven days, to keep the leaves b 
green fo long, and by the wafte of the water 
out of the veffel, that thefe boughs b muft 
have drawn much water from and through 
the other boughs and leaves c, which were 
immerfed in the veffel of water. 

I repeated the like experiment on the 
branches of Vines and Apple-trees, by run- 
ning their boughs, as they grew, into large 
glafs chymical retorts full of water 3 where 
K 3 the 

1 54 Vegetable Staticks. 
the leaves continued green for feveral 
weeks, and imbibed confiderable quantities 
of water. 

This mews how very probable it is, that 
rain and dew is imbibed by vegetables, efpe- 
cially in dry feafons. 

Which is further confirmed by experi- 
ments lately made on new -planted trees; 
where, by frequently warning the bodies of 
the moft unpromifing, they have out-ftrip- 
ped the other trees of the fame plantation. 
And Mr. Miller advifes, « Now and then 
" in an evening to water the head, and with 
€C a brufh to wafh and fupple the bark all 
" round the trunk, which (fays he) I have 
ci often found very ferviceable." 

Experiment XLIII. 

Aiiguji 20th, at i p. ?n. I took an Apple- 
branch b, (Fig. 26. ) nine feet long, 1 -j^ 
I inch diameter, with proportional lateral 
branches ; I cemented it faft to the tube a y 
by means of the leaden fyphon /: But firft 
I cut away the bark, and laft year's ringlet of 
wood, for three inches length to r. I then 
filled the rube with water, which was twelve 
feet long, and \ inch diameter, having firft 


PL -12 

p- 13 + 


Vegetable Statich. i 5 5 

cut a gap at y through the bark, and laft year's 
wood, twelve inches from the lower end of 
the ftem : the water was very freely imbibed, 
viz. at the rate of three -j- \ inches in a 
minute. In half an hour's time I could 
plainly perceive the lower part of the gap y 
to be moifter than before ; when at the fame 
time the upper part of the wound looked 
white and dry. 

Now in this cafe the water muft necef- 
farily afcend from the tube, thro' the inner- 
most wood, becaufe the laft year's wood 
was cut away, for 3 inches length, all round 
the ftem ; and confequently, if the fap in 
its natural courfe defcended by the laft 
year's ringlet of wood, and between that and 
the bark, (as many have thought) the water 
fhould have defcended by the laft year's 
wood, or the bark, and fo have firft moiftened 
the upper part of the gap y -, but on the con- 
trary, the lower part was moiftened, and not 
the upper part. 

I repeated this experiment with a large 
Duke- cherry -branchy but could not perceive 
more moifture at the upper than the lower 
part of the gap - y which ought to have been, 
if the fap defcends by the laft year's wood, 
or the bark. 

K 4 It 

\]6 Vegetable Staticks. 

It was the fame in a Quince- branch as the 
Duke- cherry. 

N. B. When I cut a notch in either of 
thefe branches, 3 feet above r, at q y I could 
neither fee nor feel any moifture, notwith- 
flanding there was at the fame time a great 
quantity of water paffing by ; for the branch 
imbibed at the rate of 4^ 3, or 2 inches per 
minute, of a column of water which was 
half inch diameter. 

The reafon of which drinefs of the notch 
q is evident from Experiment 11, viz. be- 
caufe the upper part of the branch above 
the notch imbibed and perfpired three or four 
times more water, than a column of kvtn 
feet height of water in the tube could im- 
pel from the bottom of the ftem to q, which 
was three feet length of ftem ; and confe- 
quently, the notch muft neceflarily be dry, 
notwithftanding lb large a ftream of water 
was pafling by j viz. becaufe the branch and 
ftem above the notch was in a ftrongly im- 
bibing ftate, in order to fupply the great per- 
foration of the leaves. 


Vegetable Staticks. \ 3 7 

Experiment XLIV. 

Augufl 9th, at 10 a. m. I fix'd in the fame 
manner (as in the foregoing experiment) a 
Duke-cherry-branch five feet high, and one 
inch diameter, but did not cut away any of 
the bark or wood at the great end ; I filled the 
tube with water, and then cut a flice off the 
bark an inch long, 3 inches above the great 
end ; it bled at the lower part mod freely, 
while the upper part continued dry. 

The fame day I tried the fame experi- 
ment on an Apple- branch, and it had the fame 

From thefe experiments 'tis probable, that 
the fap afcends between the bark and wood, 
as well as by other parts. 

And fince by other experiments it is 
found that the greateft part of the fap is 
raifed by the warmth of the fun on the 
leaves, which feem to be made broad and 
thin for that purpofe ; for the fame reafon, 
it's moft probable, it fhould rife alfo in thofe 
parts which are moft expofed to the fun, as 
the bark is. 

And when we confider, that the fajp-vcf- 
fels are fo very fine as to reduce the fap almoft 


138 Vegetable Staticks. 

to a vapour, before it can enter them, the 

fun's warmth on the bark fhould moft eafily 

difpofe fuch rarefied fap to afcend, inftead of 


Experiment XLV. 

July 27th, I took feveral branches of Cur- 
ram, Vines, Cherry, Apple, Pear and Plum- 
tree^ and fet the great ends of each in veffels 
of water x (Fig. 31.) 5 but firft took the bark 
for an inch off one of the branches, as at z, 
to try whether the leaves above z at b would 
continue green longer than the leaves of any 
of the other branches a, c, d-, but I could 
find no difference, the leaves withering all at 
the fame time : Now, if the return of the fap 
was flopped at z, then it would be expected, 
that the leaves at b fhould continue green lon- 
ger than thofe on the other branches; which 
did not happen, neither was there any moi- 
fture at z. 

Experiment XL VI. 

In Aitgujl, I cut off the bark for an inch 
round, of a young thriving Oak -branch, 
on the North -weft fide of the tree. The 


Vegetable Staticks. 1 3 9 

leaves of this and another branch, which 
had the bark cut at the fame time, fell early, 
viz. about the latter end of OBober y when the 
leaves of all the other branches of the fame 
tree, except thofe at the very top of the tree, 
continued on all the winter, 

This is a further proof, that lefs fap goes 
to branches which have the bark cut off, than 
to others. 

The 19th of April following, the buds of 
this branch were 5 or 7 days forwarder than 
thofe of other branches of the fame tree ; 
the reafon of which may probably be, be- 
caufe lefs frefli crude fap coming to this 
branch than the others, and the perfpira- 
tions in all branches being, cceteris paribus, 
nearly equal, the lefler quantity of fap in 
this branch muft fooner be infpiffated into 
a glutinous fubftance, fit for new produc- 
tions, than the fap of other branches, that 
abounded with a greater plenty of frefh 
thin fap. 

The fame is the reafon why Apples, 
Pears, and many other fruits, which have 
fome of their great fap-veffels eaten afun- 
der by infects bred in them, are ripe many 
days before the reft of the fruit on the 
fame trees y as alfo that fruit which is ga- 

140 Vegetable Staticks. 
thered fome time before it is ripe, will ri- 
pen fooner than if it had hung on the tree, 
tho* it will not be fo good ; becaufe in thefe 
cafes the worm- eaten fruit is deprived of part 
of its nourishment, and the green-gathered 
fruit of all. 

And for the fame reafon fome fruits are 
fooner ripe towards the tops of the trees, 
tlian the other fruit on the fame tree; viz. 
not only becaufc they are more expofed to 
the fun ; but alfo, becaufe being at a greater 
diftance from the root, they have fomewhat 
lefs nourishment. 

And this is, doubtlefs, one reafon why 
plants and fruits are forwarder in dry, fandy, 
or gravelly foils, than in moifter foils; viz. 
not only, becaufe thofe foils are warmer, 
on account of their drinefs; but alfo, be- 
caufe lefs plenty of moifture is conveyed up 
the plants; which plenty of moifture, tho' 
it promotes their growth, yet retards their 
coming to maturity. And for the fame rea- 
fon, the uncovering the roots of trees for 
fome time, will make the fruit be confiderably 
the forwarder. 

And on the other hand, where trees abound 
with too great a plenty of frefh-drawn fap, 
as is the cafe cf trees whofe roots are planted 


Vegetable Staticks. 141 

too deep in cold moift earth, as alfo of too 
luxuriant Peach and other wall trees; or, 
which comes almoft to the fame, where 
the fap cannot be perfpired off in a due pro- 
portion; as in orchards, where trees ftand too 
near each other, fo as to hinder perfpiration, 
whereby the fap is kept in too thin and crude 
a ftate ; in all thefe cafes little or no fruit is 

Hence alfo, in moderately dry fummers, 
cateris paribus, there is ufually greateft plenty 
of fruit; becaufe the fap in the bearing 
twigs and buds is more digefted, and brought 
to a better confidence, for {hooting out 
with vigour and firmnefs, than it is in 
cool moift fummers : And this obfervation 
has been verified in the years 1723, 1724, 
and 1725. See an account of them under 
it, Exper. 20. 

But to return to the fubjedl of the mo- 
tion of the fap: When the fap has firftpaffed 
thro' that thick and fine ftrainer, the bark 
of the root, we then find it in greateft quan- 
tities, in the moft lax part, between the bark 
and wood, and that the fame thro* the whole 
tree. And if in the early fpring, the Oak 
and feveral other trees were to be examined 
near the top and bottom, when the fap firft 


141 Vegetable Staticks. 

begins to move, (o as to make the bark 
eafily run, or peel off, I believe it would be 
found, that the lower bark is firft moiftened ; 
whereas the bark of the top branches ought 
firft to be moiftened, if the fap defcends by 
the bark : As to the Vine, I am pretry well 
affured that the lower bark is firft moiftened. 
See Vol II. p. 264. 

We fee in many of the foregoing expe- 
riments, what quantities of rnoifture trees 
do daily imbibe and perfpire : Now the ce- 
lerity of the fap muft be very great, if that 
quantity of rnoifture muft, moft of it, afcend 
to the top of the tree, then defcend, and 
afcend again, before it is carried oft by per- 

The defect of a circulation in vegetables 
feems in fome meafure to be iupplied by 
the much greater quantity of liquor, which 
the vegetable takes in, than the animal, 
whereby its motion is accelerated; for by 
Experiment 1. we find the fun-flower, bulk 
for bulk, imbibes and perfpires feventeen 
times more frefh liquor than a man, every 
24 hours. 

Befides, nature's great aim in vegetables 
being only that the vegetable life be carried 
on attd maintained, there was no occafion 


Vegetable Stathks. 145 

to give its fap the rapid motion which was 
necefTary for the blood of animals. 

In animals, it is the heart which fets the 
blood in motion, and makes it continually 
circulate ; but in vegetables we can difco- 
ver no other caufe of the fap's motion, but 
the ftrong attraction of the capillary fap- 
veflels, affifted by the brisk undulations and 
vibrations, caufed by the fun's warmth, 
whereby the fap is carried up to the top of 
the talleft trees, and is there perfpired oft 
thro' the leaves : But when the furface of 
the tree is greatly diminished by the lofs of 
its leaves, then alfo the perfpiration and 
motion of the fap is proportionably dimi- 
nifhed, as is plain from many of the fore- 
going experiments : So that the afcending 
velocity of the fap is principally accelerated 
by the plentiful perfpiration of the leaves, 
thereby making room for the fine capillary 
veffels to exert their vaftly attracting power, 
which perfpiration is effected by the brisk 
rarefying vibrations of warmth : A power 
that does not feem to be any ways well 
adapted to make the fap defcend from 
the tops of vegetables by different veflels 
to the root. 


144 Vegetable Stathh. 

If the fap circulated, it muft needs have 
been feen defcending from the upper part 
of large games cut in branches fet in wa- 
ter, and with columns of water prefling on 
their bottoms in long glafs tubes, in Ex- 
periment 43, and 44. In both which 
cafes, it is certain that great quantities of 
water paffed thro' the ftem, fo that it muft 
needs have been feen defcending, if the return 
of the fap downwards were by trufion or pul- 
fion, whereby the blood in animals is re- 
turned thro* the veins to the heart: And 
that pulfion, if there were any, muft necef- 
farily be exerted with prodigious force, to 
be able to drive the fap thro* the finer capil- 
laries. So that, if there be a return of rhe 
fap downwards, it muft be by attraction, 
and that a very powerful one, as we may 
fee by many of thefe experiments, and par- 
ticularly by Experiment 11. But it is hard 
to conceive, what and where that power is, 
which can be equivalent to that provifion 
nature has made for the afcent of the fap 
in confequence of the great perfpiration of 
the leaves. 

The inftances of the JefTamine tree, and 
of the Paflion tree, have been looked upon 
as ftrong proofs of the circulation of the 


Vegetable Stathks. 145 

lap, becaufe their branches, which were far 
below the inoculated Bud, were gilded: 
But we have many vifible proofs in the Vine, 
and other bleeding trees, of the Tap's recede- 
ing back, and pufhing forwards alternately, 
at different times of the day and night. 
And there is great reafon to think, that the 
fap of all other trees has fuch an alternate^ 
receding and progreffive motion, occafioned 
by the alternacies of day and night, warm 
and cool, moift and dry. 

For the fap in all vegetables does proba^ 
bly recede in fome meafure from the tops 
of branches, as the fun leaves them ; be- 
caufe its rarefying power then ceafing, the 
greatly rarefied fap, and air mixt with it, 
will condenfe, and take up lefs room than 
they did, and the dew and rain will then 
be ftrongly imbibed by the leaves, as is pro- 
bable from Exper. 42. and feveral others; 
whereby the body and branches of the ve- 
getable which have been much exhaufted by 
the great evaporation of the day, may at 
night imbibe fap and dew from the leaves; 
for by feveral Experiments in the firft chap- 
ter, plants were found to increafe consider- 
ably in weight, in dewy and moift nights. 
And by other experiments on the Vine in 

L the 

\<\6 Vegetable Staticks. 

the third chapter, ic was found, that the 
trunk and branches of Vines were always 
in an imbibing ftate, caufed by the great 
perfpirarion of the leaves, except in the 
bleeding feafon ; but when at night that 
perfpiring power ceaies, then the contrary 
imbibing power will prevail, and draw the 
fap and dew from the leaves, as well as 
moifture from the roots. 

And we have a farther proof of this in 
Experiment 12, where, by fixing mercurial 
gages to the ftems of feveral trees, which 
do not bleed, it is found that they are al- 
ways in a ftrongly imbibing ftate, by draw- 
ing up the mercury feveral inches: whence 
it is eafy to conceive, how fome of the 
particles of the gilded Bud, in the inocu- 
lated JefTamine, may be abforbed by it, 
and thereby communicate their gilding 
Miafma to the fap of other branches; efpe- 
cially when fome months after the inocu- 
lation, the ftock of the inoculated JefTa- 
mine is cut off a little above the Bud; 
whereby the ftock, which was the counter- 
acting part to the ftem, being taken away, 
the ftem attracts more vigoroufly from the 


Vegetable Statich. 147 

Another argument for the circulation of 
the fap, is that fome forts of graffs will 
infect and canker the flocks they are grafted 
on : But by Exper. 12, and 37, where mer- 
curial gages were fixed to frefh cut flems of 
trees, it is evident that thofe flems were 
in a flrongly imbibing flate ; and confe- 
quently the cankered flocks might very like- 
ly draw fap from the graft, as well as the 
graff alternately from the flock; jufl in the 
fame manner as jeaves and branches do 
from each other, in the viciffitudes of day 
and night. And this imbibing power of 
the flock is fo great, where only fome of 
the branches of a tree are grafted, that the 
remaining branches of the flock will, by 
their ftrong attraction, flarve thofe graffs; 
for which reafon it is ufual to cut off the 
greatefl part of the branches of the flock, 
leaving only a few fmall ones to draw up 
the fap. See. Vol. II, ^.265, 

The inflance of the Ilex grafted upon the 
Englijh Oak, feems to afford a very confi- 
derable argument againfl a circulation. For, 
if there were a free uniform circulation of 
the fap thro' the Oak and Ilex, why fhould 
the leaves of the Oak fall in winter, and not 
thofe of the Ilex ? 

L 2 Another 

148 Vegetable Stattch. 

Another argument againft an uniform cir- 
culation of the fap in trees, as in animals, 
may be drawn from Exper. $j. where ic 
was found by the three mercurial gages 
fix'd to the fame Vine, rhat while fome of 
its branches changed their flate of protrude- 
ing fap into a ftate of imbibing, others con- 
tinued protruding fap, one nine, and the 
other thirteen days longer. 

In the fecond Vol. of Mr. Lowthorp's 
Abridgment of the Philof. T^ranfaB, p. 708. 
is recited an Experiment of Mr. Brother- 
tons -, viz. A young Hazel n (Fig. 27.) was 
cut into the body at x z with a deep gam ; 
the parts of the body below at z> and 
above at x> were cleft upwards and down- 
wards, and the fplinters x z by wedges were 
kept off from touching each other, or the 
reft of the body. The following year, the 
upper fplinter x was grown very much, but 
the lower fplinter x did not grow 3 but the 
reft of the body grew, as if there had been 
no gafh made: I have not yet fucceeded in 
making this Experiment, the wind having 
broken at x z all the trees I prepared for 
it : But if there was a Bud at x which (hot 
out leaves, and none at z, then, by Experi- 
ment 41, 'tis plain that thofe leaves might 


Vegetable Staticks. 149 

draw muchnourifhment thro'/ x, and there- 
by make it grow -> and I believe, if, vice 
verfa, there were a leaf-bearing Bud at z> 
and none at x, that then the fpl inter z 
would grow more than x. 

The reafon of my conjecture I ground 
upon this Experiment, viz. I chofe two 
thriving moots of a dwarf Pear-tree, 1 1 a a y 
Fig. 28, 29. At three quarters of an inch 
diftance I took half an inch breadth of bark 
off each of them, in feveral places, viz, 
2,4, 6, 8, and at 10, 12, 14. Every one of 
the remaining ringlets of bark had a leaf- 
bearing bud, which produced leaves the 
following fummer, except the ringlet 13, 
which had no fuch Bud. The ringlet 9 
and 11 of a a grew and fwelled at their 
bottoms till Augujl, but the ringlet 13 did 
not increafe at all, and in Auguft the whole 
moot a a withered and died ; but the (hoot 
/ / lives and thrives well, each of its ringlets 
fwelling much at the bottom: Whch fwel- 
lings at their bottoms muft be attributed 
to fome other caufe than the floppage of 
the fap in its return downwards, becaufe in 
the (hoot //, its return downwards is in- 
tercepted three feveral times by cutting 
away the bark at 2, 4, 6. The larger and 
L 3 mors 

1 5 o Vegetable Statich. 

more thriving the leaf-bearing Bud was, and 
the more leaves it had on ir, fo much the 
more did the adjoining bark fwell at the 

Fig. 30. reprefents the profile of one of 
the divifions in Fig. 28. fplit in halves; in 
which may be feen the manner of the 
growth of the lafl; year's ringlet of wood 
mooting a little upwards at x x -, and moot- 
ing downwards and fwelling much more at 
z z 5 where we may obferve, that what is 
fhot end-ways is plainly parted from the 
wood of the preceding year, by the narrow 
interflices x r, z r\ whence it mould feem, 
that the growth of the yearly new ringlets 
of wood confiits in the mooting of their 
fibres lengthways under the bark. 

That the fap does not defcend between 
the bark and the wood, as the favourers 
of a circulation fuppofe, feems evident from 
hence, viz. that if the bark be taken off 
for three or four inches breadth quite round, 
the bleeding of the tree above that bared 
place will much abate, which ought to have 
the contrary effect, by intercepting the courfe 
of the refluent fap, if the fap defcended by 
the bark. 


Vegetable St Micks. 1 5 i 

Eut the reafon of the abatement of the 
bleeding in this cafe may well be account- 
ed for, from the man if eft proof we have 
in thefe Experiments, that the fap is ftrong- 
]y attracted upwards by the vigorous ope- 
ration of the perfpiring leaves, and attract- 
ing Capillaries : But when the bark is cut 
off for fome breadth below the bleeding 
place, then the fap which is between the 
bark and the wood below that disbarked 
place, is deprived of the ftrong attracting 
power of the leaves, &c. and confequently 
the bleeding wound cannot be fupplied fo 
fad with fap, as it was before the bark was 
taken off. 

Hence alfo we have a hint for a probable 
conjecture, why in the alternately disbarked 
flicks, 1 1 a a, Fig. 2829. the bark fwelled 
more at the upper part of the disbarked 
places than at the lower; viz, became thofe 
lower parts were thereby deprived of the 
plenty of nourifhment which was brought 
to the upper parts of thofe disbarked places 
by the ftrong attraction of the leaves on the 
Buds 7, Gfc. of which we have a further 
confirmation in the ringlet of bark, N°. i? a 
Fig. 29. which ringlet did not fwell or grow 
$t either end ? being not only deprived of 

L 4 the 

i J* Vegetable Statich. 

the attraction of the fuperior leaves, by the 
bark placed N°. 12. but alfo without any 
leaf-bud of its own, whole branching fap- 
veffels, being like thofe of other leaf-buds 
rooted downwards in the wood, might 
thence draw fap, for the nourifnment of it- 
felf and the adjoining bark, N°. 13. But 
had thefe rooting fap veffels run upwards, 
inftead of downwards, 'tis probable, that in 
that cafe the upper part of each ringlet of 
bark, and not the lower, would have fwel- 
led, by having nourifhment thereby brought 
to it from the inmoft wood. 

We may hence alfo fee the reafon why, 
when a tree is unfruitful, it is brought to 
bear fruit, by the taking ringlets of bark off 
from its branches; viz. becaufe thereby a 
lefs quantity of fap arifing, it is better di- 
gefted and prepared for the nourifhment of 
the fruit; which from the greater quantity 
of oil, that is ufually found in the feeds, 
and their containing veffels, than in other 
parts of plants, (hews that more fulphur and 
air is requifite for their production, than 
there is for the production of wood and 

But the rnoft confideratle cbjedicn 
againft this progreffive motion of the fap, 


PC & 

[ J - 1JQ 

tflL.ZZ. \ 



Vegetable Staticks. 15$ 

without a circulation, arifes from hence, 
viz. that it is too precipitate a courfe, for 
a due digeftion of the fap, in order to nu- 
trition : Whereas in animals nature has pro- 
vided, that many parts of the blood mall 
run a long courfe, before they are either 
applied to nutrition, or difcharged from the 

But when we confider, that the great 
work of nutrition, in vegitables as well as 
animals, ( I mean, after the nutriment is got 
into the veins and arteries of animals) is 
chiefly carried on in the fine capillary vef- 
fels, where nature felects and combines, as 
ihall beft fuit her different purpofes, the fe- 
veral mutually attracting nutritious particles, 
which were hitherto kept disjoined by the 
motion of their fluid vehicle; we fhall find 
that nature has made an abundant provifion for 
this work in the ftrudture of vegetables ; all 
whofecompofition is made up of nothing elfe 
but innumerable fine capillary veffels, and glan- 
dulous portions or veficles. See Vol. W.p. 265. 

Upon the whole, I think we have, from 
thefe experiments and cbfervations, fuffici- 
ent ground to believe, that there is no cir- 
culation of the fap in vegetables; notwith- 
standing many ingenious perfons have been 


f 54 Vegetable Staticks. 

induced to think there was, from leveral 
curious obfervations and experiments, which 
evidently prove, that the fap does in fome 
meafure recede from the top towards the 
lower parts of plants, whence they were 
with good probability of reafon induced to 
think that the fap circulated. 

The likelieft method effectually and con- 
vincingly to determine this difficulty, whe- 
ther the fap circulates or not, would be by 
ocular infpe&ion, if that could be attained : 
And I fee no reafon we have to defpair of 
it, fince by the great quantities imbibed and 
perfpired, we have good ground to think, 
that the progreffive motion of the fap is 
confiderable in the largeft fap-veffels of the 
tranfparent ftems of leaves: And if our eyes, 
affifted with microfcopes, could come at this 
defirable fight, I make no doubt but that 
we fhould fee the fap which was progreffive 
in the heat of day, would on the com- 
ing on of the cool evening, and the falling 
dew, be retrograde in the fame veffels. 


Vegetable Staticks. 155 


Experiments, whereby to prove, that a con- 
siderable quantity of air is i?jfpired by 

IT is well known that air is a fine ela- 
ftick fluid, with particles of very diffe- 
rent natures floating in it, whereby it is ad- 
mirably fitted by the great Author of na- 
ture, to be the breath of life of vegeta- 
bles, as well as of animals, without which 
they can no more live nor thrive, than ani- 
mals can. 

In the Experiments on Vines, Chap. III. 
we faw the very great quantity of air which 
was continually afcending from the Vines, 
thro' the fa p in the tubes; which manifestly 
fhews what plenty of it is taken in by vege- 
tables, and is perfpired off* with the fap thro* 
the leaves. 

Experiment XL VII. 

Sept. 9th, at 9 a. m. I cemented an Apple- 
branch b (Fig. 11.) to the glafs tube r i e z: 
I put no water in the tube, but fet the end 
of it in the ciftern of water x. Three 


156 Vegetable Statich. 

hours after, I found the water fucked up in 
the tube many inches to z; which fhews, 
that a confiderable quantity of air was im- 
bibed by the branch, out of the tube r i e z : 
and in like manner did the Apricot-branch 
(Exper. 29.) daily imbibe air. 

Experiment XLVIII. 

I took a cylinder of Birch with the bark 
on, 16 inches long and -| diameter, and ce- 
mented it fail at z (Fig. 32.) to the hole 
in the top of the air-pump receiver p p y 
fetting the lower end of it in the ciftern of 
water x ; the upper end of it at n was well 
clofed up with melted cement. 

1 then drew the air out of the receiver, 
upon which innumerable air-bubbles iffued 
continually out of the ftick into the wa- 
ter x. I kept the receiver exhaufted all that 
day, and the following night, and till the 
next day at noon, the air all the while if- 
fuing into the water *: I continued it thus 
long in this ftate, that I might be well af- 
fured, that the air muft pafs in through the 
bark, to fupply that great and long flux of 
air at x. I then cemented up five old eye s 
in the ftick, between z and n> where little 

(hoots had formerly been^ but were now 

perifhed \ 

Vegetable Stattcks. 157 

perifhed 5 yet the air flill continued to flow 
freely at x. 

It was obfervable in this, and many of 
the Experiments on flicks of other trees, 
that the air which could enter only thro' 
the bark between z and ?t, did not iffue in- 
to the water, at the bottom of the flick, 
only at or near the bark, but thro' the 
whole and inmofl fubflance of the wood ; 
and that chiefly, as I guefs, by the largenefs 
of the bafes of the hemifpheres of air thro* 
the largefl veflels of the wood ; which ob- 
fervation corroborates Dr. Grew's and Mal- 
fight % opinion, that they are air-vefTels. 

I then cemented upon the receiver the 
cylindrical glafs y y y and filled it full of wa- 
ter, fo as to fland an inch above the top n 
of the flick. 

The air flill continued to flow at x y but 
in an hours time it very much abated, and 
in two hours ceafed quite ; there being 
now no pafTage for frefh air to enter, and 
fupply what was drawn out of the flick. 

I then with a glafs crane drew off the 
water out of the cylinder^ y\ yet the air 
did not iflue thro* the wood at x. 

I therefore took the receiver with the 
ftick in it, and held it near the fire, till the 


1 5 8 Vegetable Statuks. 

bark was well dried ; after which I fet it 
upon the air-pump, and exhaufled the air; 
upon which the air iflued as freely at x y as 
it did before the bark had been wetted, and 
continued fo to do, tho* I kept the receiver 
exhausted for many hours. 

I fixed in the fame manner as the pre- 
ceding Birch-flick, three joints of a Vine- 
branch, which was two years old, the up- 
permofl knot r being within the receiver; 
when I pumped 5 the air pafled moft freely 
into the water x x. 

I cemented fafl the upper end of the flick n % 
and then pumped 3 the air flill iflued out at*, 
tho' I pumped very long ; but there did not 
now pafs the twentieth part of the air which 
pafled when the end n was not cemented. 

I then inverted the flick, placing n fix 
inches deep in the water, and covered all the 
bark from the furface of the water to z 
the top of the receiver with cement; then 
pumping the air which entered at the top 
of the flick, pafled thro' the immerfed pare 
of the bark: When I ceafed pumping for 
fome time, and the air had ceafed ifluing 
out; upon my repeating the pumping it 
would again iflue out. 

I found 

Vegetable Statich. 159 

I found the fame event in Birch and Mul- 
berry flicks, in both which it iffued moft plen- 
tifully at old eyes, as if they were the chief 
breathing places for trees. 

And Dr. Grew obferves, that " the pores 
<c are fo very large in the trunks of fome 
" plants, as in the better fort of thick walk- 
u ing canes, that they are vifible to a good 
" eye, without a glafs 5 but with a glafs the 
" cane feems as if it were fluck top-full of 
" holes, with great pins, being fo large as 
" very well to refemble the pores of the 
cc skin, in the end of the fingers, and ball 
" of the hand. 

" In the leaves of Pine they are likewife, 
<c thro' a glafs, a very elegant fhew, (landing 
" all moft exactly in rank and file, through 
<c the length of the leaves." Grew's Anatomy 
of Plants^ p. 127. 

Whence it is very probable, that the air 
freely enters plants, not only with the prin- 
cipal fund of nourishment by the roots, but 
alfo through the furface of their trunks and 
leaves, efpecially at night, when they are 
changed from a perfpiring to a flrongly im- 
bibing flate. 

I fix'd in the fame manner to the top of 
the air-pump receiver, but without the cy- 

\6o Vegetable Statich. 
lindrical glafs y y, the young {hoots of the 
Vine, Apple-tree, and Honeyfuckle, both 
erefted and inverted ; but found little or no 
air came either from branches or leaves, 
except what air lay in the furrows, and the 
innumerable little pores of the leaves, which 
are plainly vifible with the microfcope. I 
tried alfo the fingle leaf of a Vine, both by 
immerfing the leaf in the water x, and let- 
ting the ftalk ftand out of the receiver, as 
alfo by placing the leaf out of the receiver, 
and the ftalk in the glafs of water x-> but 
little or no air came either way. 

I obferve in all thefe Experiments, that 
the air enters very flowly at the back of 
young (hoots and branches, but much more 
freely thro' old bark: And in different kinds 
of trees it has very different degrees of more 
or lefs free entrance. 

I repeated the fame Experiment upon fe- 
veral roots of trees : The air patted moft 
freely from n to x ; and when the glafs- vef- 
felyy was full of water, and there was no 
water in x, the water paffed at the rate of 
3 ounces in 5 minutes; when the upper 
end n was cemented up, and no water in yy> 
fome air, tho' not in great plenty, would 
enftr the bark at zf, and pafs thro* the wa- 
ter at x. And 

I PL -14- 

Vegetable Stathks. \6t 

And that there is fome air both in an 
elaftick and unelaftick ftate, mix'd with the 
earth, (which may well enter the roots with 
the nourifhment) I found by putting into 
the inverted glafs z z a a full of water 
(Fig. 35.) fome earth dug up in an alley in 
the garden, which, after it had flood foaking 
for feveral days, yielded a little elaftick air, 
tho' the earth was not half diflblved. And 
in Experiment 68. we find that a cubick 
inch of earth yielded 43 cubickinches of air 
by diftillation, a good part of which was 
roufed by the action of the fire from a fixed 
to an elaftick ftate. 

I fixed alfo in the fame manner young 
tender fibrous roots, with the fmall end up- 
wards at », and the vcffel y y full of water j 
then upon pumping large drops of water fol- 
lowed each other faft, and fell into theciftern 
x, which had no water in it, See Vol II, 

A 267. 

M C H A p. 

1 6 i jinaJyfts of the Air. 

A Specimen of an attempt to analyfe the Air 
by a great variety of chymio-flatical Ex- 
periments, which Jhew in hew great a 
proportion Air is wrought into the com- 
poftion of animal, vegetable, and mineral 
Subflances, and withal how readily it re- 
fumes its former elajlick fate, when in the 
difjblution of thofe Subfances it is dif engaged 
from them, 

HAving in the preceding chapter pro- 
duced many Experiments, to prove 
that the Air is freely infpired by vegetables, 
not only at their roots, but alfo thro' feveral 
parts of their trunks and branches, which 
Air was moft vifibly fcen afcending in great 
plenty thro' the fap of the Vine, in tubes 
which were affixed to them in the bleeding 
feafon ; this put me upon making a more 
particular inquiry into the nature of a fluid, 
which is fo abfolutely neceffary for the fup- 
port of the life and growth of Animals and 

The excellent Mr. Boyle made many Ex- 
periments on the Air, and among other dif- 


Analyfis of the Air. 1 6 $ 

coveries, found that a good quantity of Air 
was producible from Vegetables, by putting 
Grapes, Plums, Goofeberries, Cherries, Peas, 
and feveral other forts of fruits and grains 
into exhaufted and unexhaufled recei\%s, 
where they continued for feveral days emit- 
ting great quantities of Air. 

Being defirous to make fome further re- 
fearches into this matter, and to find what 
proportion of this Air I could obtain cut 
of the different fubftances in which it was 
lodged and incorporated, I made the fol- 
lowing chymio-ftatical Experiments : For, 
as whatever advance has here been made in 
the knowledge of the nature of Vegetables, 
has been owing to flatical Experiments, fo, 
fince nature, in all her operations, acts con- 
formably to thofe mechanick laws, which 
were eftablifhed at her firft inflitution - ? it 
is therefore reafonable to conclude, that the 
likeliefh way to inquire, by chymical ope- 
rations, into the nature of a fluid, too fine 
to be the object of our fight, mud be by 
finding out fome means to eftimate what 
influence the ufual methods of analyfing 
the animal, vegetable, and mineral king- 
doms, has on that fubtle fluid $ and this I 
effected by affixing to retorts and boltheads 
M 2 hydro- 

1 64 Analyfis of the Ah. 

hydroftatical gages, in the following man- 
ner, viz. 

In order to make an eftimate of the quan- 
tity of x^ir which arofe from any body by 
diftillation or fufion, I firft put the matter 
which I intended to diftil into the fmall 
retort r (Fig. 33.) ; and then at a cemented 
faft to it the glafs veffel a b y which was very 
capacious at £, with a hole in the bottom. 
I bound bladder over the cement which was 
made of tobacco-pipe clay and bean flour, 
well mixed with fome hair, tying over all 
four fmall flicks, which ferved as fplinters 
to ftrengthen the joint ; fometimes, inftead 
of the glafs veflel a b, I made ufe of a large 
bokhead, which had a round hole cut, with 
a red hot iron ring at the bottom of it; 
through which hole was put one leg of an 
inverted fyphon, which reached up as far as 
z. Matters being thus prepared, holding 
the retort uppermoft, I immerfed the bolt- 
head into a large veflel of water, to a the 
top of the bolthead ; as the water rufhed in 
at the bottom of the bolthead, the Air was 
driven out through the fyphon: When the 
bolthead was full of water to z, then I clofed 
the outw 7 ard orifice of the fyphon with the 
end of my finger, and at the fame time drew 


Analyfis of the Air. 1 6 j 

the other leg of it out of the bolthead ; by 
which means the water continued up to z y 
and could not fubfide. Then I placed under 
the bolthead, while it was in the water, the 
veffel xx ; which done, I lifted the veffel x x y 
with the bolthead in it, out of the water, 
and tied a waxed thread at z to mark the 
height of the water : And then approached 
the retort gradually to the fire, taking care 
to fcreen the whole bolthead from the heat 
of the fire. 

The defcent of the water in the bolthead 
{hewed the fums of the expanfion of the 
Air in the retort, and of the matter which 
was diftilling : The expanfion of the Air 
alone, when the lower part of the retort was 
beginning to be red hot, was, at a medium, 
nearly equal to the capacity of the retorts, fo 
that it then took up a double fpace ; and in 
a white and almoft melting heat, the Air took 
up a triple fpace, or fomething more : for 
which reafon the leaft retorts are beft for 
thefe Experiments. The expanfion of the 
diftilling bodies was fometimes very little, 
and fometime many times greater than that 
of the Air in the retort, according to their 
different natures. 

M ? When 

1 66 Jnalyjis of the Air. 

When the matter was fufficiently diflilled, 
the retort, &c. was gradually removed from 
the fire j and when cool enough, was carried 
into another room, where there was no fire. 
When all was throughly cold, either the 
following day, or fometimes three or four 
days afier, I marked the furface of the water 
v, where it then flood j if the furface of the 
water was below z, then the empty fpace 
between y and z (hewed how much Air was 
generated, or raifed from a fix'd to an ela- 
ftick ftate, by the aftion of the fire in diftil- 
lation : But if v, the furface of the water, 
was above z, the fpace between z and r, 
which was filled with water, fhewed the 
quantity of Air which had been abforbed in 
the operation, i. e. was changed from a re- 
pelling elaflick to a fix'd ftate, by the flrong 
attraction of other particles, which I there- 
fore call abforbing. 

When I would meafure the quantity of 
this new generated air, I feparated the bolt- 
head from the retort ; and putting a cork 
into the fmall end of the bolthead, I inverted 
it, and poured in water to z. Then from 
another vefTel ( in which I had a known 
quantity of water by weight) I poured iri 
water to *j fo the quantity of water which 

Analyfis of the Ah. \ 67 

was wanting, upon weighing this veffel again, 
was equal to the bulk of the new generated 
Air. I chofe to meafure the quantities of Air, 
and the matter from whence it arofe, by 
one common meafure of cubick inches, 
eftimated from the fpecifick gravities of the 
feveral fubftances, that thereby the propor- 
tion of one to the other might the more 
readily be feen. 

I made ufe of the following means to 
-meafure the great quantities of Air, which 
were either raifed and generated, or ab- 
forbed by the fermentation arifing from the 
mixture of variety of folid and fluid fub- 
ftances, whereby I could eafily eftimate the 
furprizing effeds of fermentation on the 
Air; viz. 

I put into the bolthead b (Fig. 34.) the 
ingredients, and then run the long neck of 
the bolthead into the deep cylindrical glafs 
ay, and inclined the inverted glafs ay, and 
bolthead, almoft horizontally in a large vef- 
felj of water, that the water might run into 
the glafs a y\ when it was almoft up to a 
the top of the bolthead, I then immerfed 
the bottom of the bolthead, and lower part 
y of the cylindrical glafs under water, rait- 
ing at the fame time the end a uppermoft. 

M 4 Then, 

1 68 Analyfis of the Ah. 

Then, before I took them out of the water, 
I fet the bolthead and lower part of the cylin- 
drical glafs a y into the earthen veffel x x, 
full of water ; and having lifted all out of 
the great veffel of water, I marked the fur- 
face z of the water in the glafs ay. 

If the ingredients in the bolthead, upon 
fermenting, generated Air, then the water 
would fall from z toy, and the empty fpace 
z y was equal to the bulk of the quantity 
of Air generated : But if the ingredients, 
upon fermentation, did abforb or fix the 
2c~tive particles of Air, then the furface of 
the v/ater would afcend from z to n 9 and 
the fpace z ;/, which was filled with water, 
was equal to the bulk of Air, which was 
abforbed by the ingredients, ox by the fume 
arifing from them : When the quantities of 
Air, either generated or abforbed, were very 
great, then I made ufe of large chymical re- 
ceivers inflead of the glafs a y: But if thefe 
quantities were very fmall, then, inftead of 
the bolthead, and deep cylindrical glafs a y\ 
I made ufe of a fmall cylindrical glafs, or 
a common beer glafs inverted, and placed 
under it a phial or jelly-giafs, taking care that 
the water did not come at the ingredients 
in them., which was eafily prevented by 


VLi 5 



Jnalyfis of the Air. \ 6 9 

drawing the water up under the inverted 
glafs to what height I pleafed by means of 
a fyphon : I meafured the bulk of the fpaces 
z y or z n y by pouring in a known quan- 
tity of water, as in the foregoing Experi- 
ment, and making an ' allowance for the 
bulk of the neck of the bohhead within 
the fpace z y. 

When I would take an eftimate of the 
quantity of Air abforbed and fixed, or ge- 
nerated by a burning candle, burning brim- 
ftone or nitre, or by the breath of a living 
animal, &c. I firfl placed a high fland, or 
pedeftal in the veflel full of water x x 
(Fig. 3 5.) -, which pedeftal reached a little 
higher than z z. On this pedeftal I placed 
the candle, or living animal, and then 
whelmed over it the large inverted glafs 
z z a a, which was fufpended by a cord, 
fo as to have its mouth r r three or four 
inches under water ; then with a fyphon I 
fucked the Air out of the glafs veflel, till the 
water rofe to z fe. But when any noxious 
thing, as burning brimftone, aquafortis, or 
the like, were placed under the glafs ; then 
by affixing to the fyphon the nofe of a large 
pair of bellows, whofe wide fucking orifice 
was clofed up, as the bellows were inlarged, 

liic V 

1 7 o Analyjis of the Air. 

they drew the Air briskly out of the glafs 
z z a a thro* the fyphon ; the other leg of 
which fyphon I immediately drew from under 
the glafs veflel, marking the height of the 
water z z. 

When the materials on the pedeftal ge- 
nerated Air, then the water would fubfide 
from zz to a a, which fpace z z a a was 
equal to the quantity of Air generated : But 
when the materials deflroyed any part of the 
Air's elafticity, then the water would rife 
from a a (the height that I in that cafe at 
firft fucked it to) to z z, and the fpace aazz 
was equal to the quantity of air, whofe elafti- 
city was deflroyed. 

Ifomeiimes fired the materials on the pe- 
deftal by means of a burning glafs, viz. fuch 
as phofphorus and brown paper dipped in 
water, ftrongly impregnated with nitre, and 
then dried. 

Sometimes I lighted the candle, or large 
matches of brimftone, before I whelmed the 
glafs zz a a over them -, in which cafe I 
inftantiy drew up the water to a a, which 
by the expanfion of the heated Air would 
at firft fubfide a little, but then immediately 
turned to a rifing ftate; notwithftanding the 
flame continued to heat and rarefy the Air 


Analyjis of the Air. \ y \ 

for two or three minutes : As foon as the flame 
was out, I marked the height of the water 
z z-, after which the water would for twenty 
or thirty hours continue rifing a great deal 
above z z. 

Sometimes, when I would pour violently 
fermenting liquors, as aquafortis, &t\ on any 
materials, I fufpendedthe aquafortis in a phial 
at the top of the glafs velTel z z a a 3 in fuch 
manner, that by means of a firing, which 
came down into the veffel x x, I could by 
inverting the phial pour the aquafortis on 
the materials, which were in a veiTel on the 

I fhall now proceed to give an account of 
the^event of a great many Experiments, which 
I made by means of thefe inftruments, which 
I have here at firft defcribed, to avoid the fre- 
quent repetition of a defcription of 'em. 

It is confonant to the right method of phi- 
lofophifing, firft, to analyfe the fubjecl:, 
whofe nature and properties we intend to 
make any refearches into, by a regular and 
numerous feries of Experiments : And then, 
by laying the event of thofe Experiments be- 
fore us in one view, thereby to fee what 
jight their united and concurring evidence 


1 7 1 jinalyjis of the Air. 

will give us. How rational this method is, 

the fequel of thefe Experiments will (hew. 

The illuftrious Sir Ifaac Newton (query 
31ft of his Opticks) obferves, That " true 
« c permanent Air arifcs by fermentation or 
« c heat, from thofe bodies which the chy- 
<c mifts call fixed, whofe particles adhere by 
" a ftrong attraction, and are not therefore 
" feparated and rarefied without fermenta- 
" tion ; thofe particles receding from one 
" another with the greater! repulfive force, 
" and being molt difficultly brought toge- 
" ther, which upon contact: were moil 
u ftrongly united." And, query 30. "Denfe 
cc bodies by fermentation rarefy into feveral 
" forts of Air ; and this Air by fermen- 
<c tation, and fometimes without it, re- 
<c turns into denfe bodies." Of the truth of 
which we have evident proof from many of 
the following Experiments, viz. 

That I might be well affured that no part 
of the new Air which was produced in di- 
ftillation of bodies, arofe either from the 
greatly heated Air in the retorts, or from 
the fubftance of the heated retorts, I firft 
gave a red hot heat both to an empty glafs 
retort, and alfo to an iron retort made of a 
musket barrel ; when all v/as cold, I found 


Analyfis of the Air. \ 7 } 

the Air took up no more room than before it 
was heated : whence I was allured, that no 
Air arofe, either from the fubftance of the re- 
torts, or from the heated air. 

As to animal fubjlancesy a very confiderable 
quantity of permanent Air was produced by 
diftillation, not only from the blood and fat, 
but alfo from the moft folid parts of animals. 

Experiment XLIX. 

A cubick inch of Hogs blood> diftilled to 
dry fcoria, produced 33 cubick inches of Air, 
which Air did not arife till the white fumes 
arofe ; which was plain to be fctn by the 
great defcent of the water at that time, in the 
receiver az y (Fig. 33.) 

Experiment L. 

Lefs than a cubick inch of Tallow, being all 
diftilled over into the receiver a z y, (Fig. 33.) 
produced 18 cubick inches of Air. 

Experiment LI. 

241 Grains, or half a cubick inch of the 
lip of zjalhw Deers horn, being diftilled in 


t 7 4 Analyjis of the Ah. 

the iron retort, made of a musket barrel, 
which was heated at a fmith's forge, pro- 
duced 117 cubick inches, that is, 234 times 
its bulk of Air, which did not begin to rife 
till the white fumes arofe; but then rufhed 
forth in great abundance, and in good plenty, 
alio with the fetid oil which came laft. The 
remaining calx was two thirds black, the reft 
afli-coloured; it weighed 128 grains, fo it 
was not half wafted, whence there muft re- 
main much fulphur in it ; the weight of water 
to Air being nearly as 885 to one, as Mr. 
Hawksbee found it, by an accurate Experi- 
ment. A cubick inch of Air will weigh -| of 
a grain, whence the weight of air in the horn 
was 33 grains, that is, near \ part of the 
whole horn. 

We may obfcrve in this, as alfo in the pre- 
ceding Experiment, and many of the follow- 
ing ones, that the particles of new Air were 
detached from the blood and horn, at the 
fame time with the white fumes, which con- 
ftitute the volatile fait: But this volatile fait, 
which mounts with great adtivity in the Air, 
is fo far from generating true elaftick Air, that 
on the contrary it abforbs it, as I found by the 
following Experiment. 


Analyfis of the AW. 1 7 5 

Experiment LII. 

A dram of volatile fait offal armoniack 
foon diftilled over with a gentle heat 5 but 
tho' the expanfion in the receiver was double 
that of heated Air alone, yet no Air was ge- 
nerated, but two and an half cubick inches 
were abforbed. 

Experiment LIII. 

r Half a cubick inch of Oyfter-Jbell, or 266 
grains, diftilled in the iron retort, generated 
162 cubick inches, or 46 grains, which is a 
little more than £ part of the weight of 
the (hell. 

Exp er 1 men t LIV. 

Two grains of Phofphorus eafily melted 
at fome diftance from the fire, flamed and 
filled the retort with white fumes \ it ab- 
forbed three cubick inches of Air. A like 
quantity of Phofphorus^ fired in a large re- 
ceiver, (Fig. 35.) expanded into a fpace equal 
to fixty cubick inches, and abforbed 28 cu- 
bick inches of Air: When three grains of 
Phofphorus were weighed, foon after it was 
burnt, it had loft half a grain of its weight; 
but when two grains of Phofphorus were 


1 7 6 Analyjls of the Air. 

weighed, fome hours after it was burnt, hav- 
ing run more per deliquhim by abforbing the 
moifture of the Air, it had increafed a grain 
in weight. 

Experiment LV. 

As to vegetable fubftances, from half a 
cubick inch, or 135 grains of heart of Oak i 
frefh cut from the growing tree, were gene- 
rated 108 cubick inches of Air, u e. a quan-> 
tity equal to 2 16 times the bulk of the piece 
of Oak-, its weight was above thirty grains, 
-J. part of the weight of 135 grains of Oak. 
I took a like quantity of thin fhavings from 
the fame piece of Oak, and dried them gently 
at fome diftance from a fire for twenty-four 
hours, in which time 44 grains weight of 
moifture had evaporated ; which being de- 
ducted from the 135 grains, there remain 91 
grains for the folid part of the Oak : Then 
the 30 grains of Air will be -| of the weight 
of the folid part of the Oak. 

Eleven days after this Air was made, I put a 
live Sparrow into it, which died inftantly* 

Experiment LVI. 

From 388 grains weight of Indian Wheat \ 

which grew in my garden, but was not 


Analyjis of the Air. 17 7 

come to full maturity, were generated 270 
cubick inches of air, the weight of which 
air was 77 grains, viz. \ of che weight 
of the Wheat. 

Experiment LVII. 

From a cubick inch, or 318 grains of 
Peas, were generated 396 cubick inches of 
air, or 113 grains, i. e. fomething more 
than ■ of the weight of the Peas. 

Nine days after this air was made, I 
lifted the inverted mouth of the receiver 
which contained it, out of the water, amd 
put a lighted candle under it, upon which 
it inftantly flafhed: Then I immediately im- 
merfed the mouth of the receiver in the wa- 
ter, to extinguilh the flame: This I repeated 
8 or 10 times, and it as often flafhed, after 
which it ceafed, all the fulphureous fpirrt be- 
ing burnt. It was the fame with air of di- 
ftilled Oyfter-fhell and Amber, and with new 
diftilled air of Peas and Bees-wax. I found 
it the fame alfo with another like quantity 
of air of Peas; notwithstanding I wafhed 
that air no lefs than eleven times, by pour- 
ing it fo often under water, upwards, out 
of the containing vefleL into another in- 
verted receiver full of water, 

N ExpE- 

1 7 8 Ana l)fis of the Ah. 

Experiment L VIII. 

There were raifed from an ounce, or 437 
grains of Mujlard-jeed, 270 cubick inches 
of air, or yy grains; which is fomething 
more than £ part of the ounce weight. 
There was doubtlefs much more air in the 
feed , but it rofe in an unelaftick ftate, be- 
ing not difentangled from the Oil, which 
was in fuch plenty within the gun-barrel, 
that when I heated the whole barrel red hot, 
in order to burn it our, it flamed vigoroufly 
out at the mouth of the barrel. Oil alfo 
adhered to the infide of the barrel, in the 
diftillation of many of the other animal, 
vegetable, and mineral fubftances ; fo that 
the elaftick air which I meafured in the re- 
ceiver, was not all the air contained in the 
feveral diftill'd fubftances; fome remaining 
in the Oil, for there is unelaftick air in Oil, 
part being alfo reforbed by the fulphureous 
fumes in the receiver. 

Experiment LIX. 

From half a cubick inch of Amber, or 
135 grains, were raifed 135 cubick inches 
of air, or 38 grains, viz. j\j P art °f * ts 
weight. E x p e- 

Analyfls of the Air. 179 

Experiment LX. 

From 142 grains of fay 'Tobacco were raifed 
153 cubick inches of air, which is little 
lefs than | of the whole weight of the To- 
bacco ; yet it was not all burnt, part being 
out of the reach of the fire* 

Experiment LXI. 

Camphire is a moft volatile fulphureous 
fubftance fublimed from the Rofin of a tree 
in the Eajl-Indies. A dram of it melted 
into a clear liquor, at fome diflance from 
the fire, and fublimed in the form of white 
cryftals, a little above the liquor, it made 
a very fmall expanfion, and neither gene- 
rated nor abforbed air. The fame Mr. Boyle 
found, when he burnt it in vacuo, Vol II. 
p. 605. 

Experiment LXIL 

From about a cubick inch of chymical 
Oil of Anifeed, I obtained 22 cubick inches 
of air 5 and from a like quantity of Oil of 
Olives, 88 cubick inches of air. Finding 
that the Oil of Anifeed came plentifully 
over into the receiver, in the diftillation of 
N 2 the 

1 8o Atialyjis of the Air. 

the Oil of Olives, I raifed the neck of the 
retort a foot higher ; by which means the 
Oil could not fo eafily afcend, but fell back 
again into the hottefl part of the retort; 
whereby, as well as on account of the lefs 
volatile nature of this Oil, more air was 
feparated j yet in this cafe good flore of Oil 
came over into the receiver ; in which 
there was doubtlefs plenty of unelaftick 
air : Whence, by comparing this with Ex- 
periment 58, we fee that air is in greater 
plenty feparated from the Oil, when in the 
Muftard- feed, than it is from exprefTed or 
chymical Oil. 

Experiment LXIII. 

From a cubick inch, or 359 grains of Ha- 
?iey y mixed with calx of bones, there arofe 
144 cubick inches of air, or 41 grains, viz. 
a little more than -£ part of the weight of 
the whole. 

Experiment LXIV. 

From a cubick inch of yellow Bees-wax, 
or 243 grains, there arofe 54 cubick inches 
of air, or 15 grains -, the ^ part of the 


Analyjis of the Ait. 1 8 1 

Experiment LXV. 

From 373 grains, or a cubick inch of, 
the, coarfeft Sugar, which is the effential 
fait of the fugar-cane, there arofe 126 cu- 
bick inches of air, equal to 36 grains, a lit- 
tle more than 7V part of the whole. 

Experiment LX VI. 

I found very little air in 54 cubick inches 
of Brandy, but in a like quantity of Well- 
water I found one cubick inch. And it 
was the fame in a little quantity of Brijlol 
hot well water, and of Holt water. In 
Piermont water there is near twice as much 
air, as in Rain or common water, which air 
contributes to the brisknefs of that and 
many other mineral waters. I found thefe 
feveral quantities of air, in thefe waters, 
by inverting the nofes of bottles full of 
thefe feveral liquors, into fmall glafs cif- 
terns full of the fame liquor; and then 
fetting them all together in a boiler, where 
having an equal heat, the air was thereby 
feparated, and afcended to the upper parts 
of the bottles. See Vol. II. p. 269, 272. 

N 3 Expe- 

1 8 z Analyfis of the Air. 

Experiment LXVJI. 

By the fame means alfo, I found plenty 
of air might be obtained from minerah. 
Half a cubick inch, or 158 grains of New- 
caflle coal, yielded in diftillation 180 cu- 
bick inches of air, which arofe very fad 
from the coal, efpecially when the yel- 
lowifh fumes afcended. The weight of this 
air is 5 1 grains, w T hich is nearly ■§■ of the 
weight of tne coals. 

Experiment LXVIII. 

A cubick inch of freih dug untried Earth 
off the common, being well burnt in diftil- 
lation, produced 43 cubick inches of air. 
From Chalk alfo I obtained air in the fame 

Experiment LXIX. 

From a quarter of a cubick inch of An- 
timo?iy y I obtained 28 times its bulk of air. 
It was diftilled in a glafs retort, becaufe it 
will demetalize iron. 

Experiment LXX. 

I proc red a hard, dark, grey Pyrites, a 
vitriolick miner aljubjlance, which was found 

7 feet 

Analyjis of the Air. 1 8 j 

7 feet under ground, in digging for fprings 
on Walton-Heath y for the fervice of the 
Right Honourable the Earl of Lincoln, at 
his beautiful Seat at Oatlands in Surrey. This 
mineral abounds not only with fulphur, 
which has been dra^vn from it in good plen- 
ty, but alfo with faline particles, which 
fnoot vifibly on its furface. A cubick inch 
of this mineral yielded in distillation 83 
cubick inches of air. 

Experiment LXXI. 
Half a cubick inch of well decrepitated 
Sea-falty mix'd with double its quantity of 
calx of bones, generated 32 times its bulk 
of air: It had fo great a heat given it, that 
all being diftilled over, the remaining fco- 
ria did not run per deliquium. I cleared 
the gun-barrel of thefe and the like (bo- 
na, by laying the end of the retort on an 
anvil, and ftriking long on the outfide with 
a hammer. 

Experiment LXXII. 

From 211 grains, or half a cubick inch 
of Nitre, mixed with calx of bones, there 
arofe 90 cubick inches of air, /. e. a quanti- 
ty equal to 180 times its bulk ; fo the weight 

N 4. of 

1 84 Anatyfes of the Aw. 

of air in any quantity of nitre is about \ 
part. Vitriol diftilled in the fame manner 
yields air too. 

Experiment LXXIII. 

From a cubick inch, or 443 grains of 
Kenijh 'Tartar, there arofe very fall 504 cu- 
bick inches of air ; fo the weight of the air 
in this Tartar was 144 grains, ;. e. \ part of 
the weight of the whole: The remaining 
fcoria, which was very little, run per deli- 
quium, an argument that there remained 
fome Sal Tartar % and confequently more air. 

Experiment LXXIV. 

Half a cubick inch, or 304 grains of Sal 
Tartar, made with nitre and tartar, and 
mixed with a double quantity of calx of 
bones, yielded in diftillation 112 cubick 
inches of air; that is, 224 times its bulk 
of air; which 112 cubick inches weighing 
32 grains, is nearly ■§ part of the weight of 
the Sal Tartar. There is a more intenfe de- 
gree of heat required to raife the air from 
Sal Tartar than from nitre. 

Hence we fee, that the proportion of 
air in equal bulks of Sal Tartar and nitre is 


Analyjls of the Air, 185 

as 224 to 180. But weight for weight, nitre 
contains a little more air in it, than this Sal 
Tartar made with nitre. But Sal Tartar 
made without nitre, has probably a little 
more air in it than this had, becaufe it is 
found to make a greater explofion in the 
Pulvis Fulminans, than the nitrated Sal 
Tartar. But fuppofing, as is found by this 
Experiment, that Sal Tartar, according to 
its fpecifick gravity, contains j part more 
in it than nitre ; yet this excefs of air is not 
fufficient to account for the vaftly greater 
explofion of Sal Tartar than of nitre ; which 
feems principally to arife from the more 
fix'd nature of Sal Tartar $ which therefore 
requires a more intenfe degree of fire, to 
feparate the air from the ftrongly adhering 
particles, than is found requifite to raife the 
air from nitre. Whence the air of Sal Tar- 
tar muft neceffarily thereby acquire a greater 
elaftick force, and make a more violent ex- 
plofion, than that of nitre. And from the 
fame reafon it is, that Aurum Fulmiiiam 
gives a louder explofion than Pulvis Ful- 
minant. The fcoria of this operation did 
not run per deliquium, a proof that all the 
Sal Tartar was diftilled over. See Vol. II. 
p. 282. 


i86 Analjfis oj the Air. 

From the little quantity of air which is 
obtained by the diftillation of that very fixe 
body fea-falt, in Experiment 71. in compa- 
rifon of what arifes from nitre and Sal Tar- 
tar y we fee the reafon why it will not go 
off with an explofive force, likethofe when 
fired. And at the fame time we may hence 
obferve, that the air included in nitre and 
Sal Tartar, bears a confiderable part in their 
cxplofion. For fea-falt contains an acid 
fpirit as well as nitre; an v d yet that without 
a greater proportion of air does not qualify 
it for explofion, thro* mixed like nitre in the 
compofition of gun-powder, with fulphur 
and charcoal. 

Mr. Boyle found, that Aqua-fortis,}pouxzA 

on a ftrong folution of fait of tartar, did not 
fhoot into fair cryflals of falt-petre, till it 
had been long expofed to the open air ; 
whence he fufpected, that the air contribu- 
ted to that artificial production of falt-petre. 
And fays, " Whatever the air hath to do in 
" this Experiment, we have known fuch 
<c changes made in fome faline concretes > 
<c chiefly by the help of the open air, a 
(i very few would be apt to imagine." Vol. 
I. p. 302. and Vol III. p. 80. And Chy- 
rnifts obferve, that when the elTential falts 


Jnalyjis of the Air. 1 87 

of vegetables are fet to cryftallize, it is 
needful to take off the skin or Pellicle, 
which covers the liquor, before the falts 
will (hoot well. 

We fee from the great quantity of air, 
which is found in falts, of what ufe it is 
in their cryflallization and formation; and 
particularly, how neceflary it is in making 
falt-petre from the mixture of fait of tartar, 
and fpirit of nitre. For fince, by Experiment 
72 and 73, a great deal of air flies away, in 
the making of Sal Tartar, either from nitre 
and tartar, or from tartar alone ; it muft 
needs be neceflary, in order to the forming 
of nitre from the mixture of Sal Tartar and 
fpirit of nitre, that more air fhould be in- 
corporated with it, than it contained either 
in the Sal Tartar or fpirit of nitre. 

Experiment LXXV. 

Near half acubickinch of compound Aqua- 
fortis, which bubbled, and made a con- 
siderable expanfion in diftillation, was foon 
diftilled off: as it cooled, the expanfion 
abated very fa ft, and a little air was abforb- 
ed. Whence it is evident, that the air ge- 
nerated by the diftillation of nitre, did not 
arife from the volatile fpirituous particles. 


1 88 Analyfis of the Air. 

Hence alfo it is probable, that there is 
fome air in acid fpirirs, which is reforbed 
and fixed by them in diftillation. And this 
is furth crconfirmed from the many air- 
bubbles which arife from Aqua-regia y in 
the folution of gold ; for fince gold lofes 
nothing of its weight in being diflblved, the 
air cannot arife from the metalline part of 
the gold, but muft either arife from the 
Aqua-regia, or from latent air in the pores 
of the gold. 

Experiment LXXVJ. 

A cubick inch of common Brimflone ex- 
panded very little in diftrllation in a glafs 
retort; notwitbftanding it had a great heat 
given it, and was all diftilled over into the 
receiver without flaming. It abforbed fome 
air ; but flaming brimflone, by Experiment 
103, abforbs much air. 

A good part of the air thus raifed from 
feveral bodies by the force of fire, was apt 
gradually to loofe its elaflicity, in ftanding 
feveral days -, the reafon of which was, ( as 
will appear more fully hereafter) that the 
acid fulphureous fumes railed with that air, 
did rel'orb and fix the elaftick particles. 


Analyjis of the Air. 189 

Experiment LXX VII. 

To prevent which, I make ufe of the fol- 
lowing method of diftillation, which is 
much more commodious than with Glafs 
Retorts, whofe juncture at a (Fig. 33.) it is 
not eafy to fecure. Having firft put the 
matter to be diftilled into the iron retort 
r r (Fig. 38.) which was made of a musket 
barrel, I then fixed a leaden fyphon to the 
nofe of the retort 5 and having immerfed 
the fyphon in the veffel of water x x, I 
placed over the open end of the fyphon the 
inverted chymical receiver a i y which was 
full of water ; fo that, as the air which was 
raifed in diftillation, paffed thro* the water 
up to the top of the receiver a b, a good 
part of the acid fpirit and fulphureous fumes 
were by this means intercepted and retain- 
ed in the water ; the confequence of which 
Was, that the new generated air continued 
in a more permanently elaftic'k ftate, very 
little of it lofmg its elasticity, viz. not 
above a 15th or 18th part, and that chiefly 
the firft 24 hours ; after which the remain- 
der continued in a conftantly elaftick ftate , 
excepting the airs of tartar and calcullus hu- 
ymnus, which in 16 or 8 days loft conftantly 


ipo Analyjis of the Air. 

above one third of their elaflicity 5 aftef 
which the remainder was permanently ela- 
ftical. In which flate it has continued, 
without any fenfible alteration, for thefe 
fix years, that I have kept fome of the 
air of calculus humanus by me. 

That the great quantities of air, which are 
thus obtained from thefe feveral fubflances 
by diftillation, are true air, and not a mere 
flatulent vapour, I was afTured by the fol- 
lowing Trials; viz. I filled a large receiver, 
which contained 540 cubick inches, with air 
of tartar; and when it was cool, Ifufpended 
the receiver on the end of a balance while its 
mouth was inverted in water. Then, upon 
lifting the mouth of the receiver out of water, 
I immediately covered it by tying a piece of 
bladder over it. When I had found the ex- 
ad: weight, I blew out all the air of tartar 
with a pair of bellows which had a long ad- 
ditional nofe that reached to the bottom of 
the receiver. And then tying the bladder 
on, I weighed it again, but could find no 
difference in the fpecifick gravity of the two 
airs -, and it was the fame with an air of 
tartar, which was 10 days old. 

As to the other property of the air, elafli- 
city, I found it exa&ly the fame in the air 


Analyjis of the Jir. '191. 

of tartar, which was 15 days old, and com- 
mon air, by filling two equal tubes with 
thefe different airs, the tubes were 10 inches 
long, and fealed at one end ; I placed them 
at the fame time in a cylindrical glafs con- 
denfing receiver, where I compreffed them 
with two additional atmofpheres, taking 
care to fecure myfelf from danger in cafe 
the glafs fliould burft, by placing it in a 
deep wooden vcffel 5 the water rofe to equal 
heights in both tubes. This receiver was 
gently annealed, and thereby toughened, by 
being boiled in Urine, where it lay till all 
was cold. 

I put alfo into the fame tubes fome new- 
made air of tartar, both the tubes Handing 
in cifterns of water; the air of one of thefe 
tubes I compreffed in the condenfing en- 
gine for fome days, to try whether in that, 
compreffed ftate, more of the air's elafticity 
would be deftroyed by the abforbing vapours, 
than io an uncompreffed ftate; but I did 
not perceive any fenfible difference. 

Lemery\ in his courfe of chymiftry, p, 592. 
obtained, in the diftillation of 48 ounces of 
Tartar, 4 ounces of phlegm, 8 of fpirits, 
3 of oil, and 32 of fcoria, L e. two thirds 
of the whole; fo one ounce was loft in the 
operation, In 

lyi Analyjis of the Air. 

In my diftillation of 443 grains of Tar- 
tar m Exper. 73. there remained but 42 
grains of fcoria, which is little more than 
7 V of the Tartar; and in this remainder, 
there was, by Exper. 74. air; for there was 
Sal Tartar , it running per deliquiujn. 

Whence, by comparing Lemery's and my 
diftillation together, we fhall find, that there 
remained in this 32 ounces of fcoria, and 
in the ounce that was loft, ( which was 
doubtlefs moft of it air) fubftance enouah to 
account for the great quantity of air, which 
in Exper. 73. was raifed from Tartar; efpe- 
cially, if we take into the account the pro- 
portion of air, which was contained in the 
oil, which was T ^ part of the whole Tar- 
tar, for there is much air in oH. 

The bodies which I diftilled in this man- 
ner, ( Fig. 38.) were Horn, Calculus lnimamis y 
Oyfter-fhcll, Oak, Muftard-feed, Indian- 
wheat, Peas, Tobacco, oil of Anifeed, oil 
of Olives, Honey, Wax, Sugar, Amber, Coal, 
Earth, Walton Mineral, Sea-falt, Salt-petre, 
Tartar, Sal Tartar, Lead, Minium. The 
greateft part of the air obtained from all 
which bodies was very permanent, except 
what the air of Tartar and calculus humanus 
loft in ftanding feveral days. Particularly that 



Analyjis of the Air. 193 

from nitre loft little of its elafticity, where- 
as moft of the air obtained from nitre, in 
diftilling with the receiver (Fig. 33.) was 
reforbed in a few days, as was alfo the air 
which was generated from detonized nitre 
in Experiment 102. Hence alfo we fee the 
reafon why 19 parts in 20, of the air which 
was generated by the firing of Gunpowder* 
was in 18 days reforbed by the fulphureous 
fumes of the Gunpowder -, as Mr. Hawksbee 
obferved, in his phyfico-mechanical Experi- 
ments, page 83. 

In the diftillation of Horn, it was obferv- 
able, that when towards the end of the ope- 
ration the thick fetid oil arofe, it formed 
very large bubbles, with tough unctuous 
skins, which continued in that flate forne 
time; and when they broke, there arofe 
t)ut of them volumes of fmoak, as out of 
•a chimney, and it was the fame in the di- 
stillation of Muftard-feed. 

An Account of some Experiments made 

on Stones taken ou t of human 
Urine, and Gall-bladders. 


Aving procured, by the favour of Mr. 
Ranby, Surgeon to His Majejtfs 

O Roupjcti, 

1 94 Analyfis of the Air. 
Houjho/d, fome calculi humanly I made the 
following Experiments with them, which I 
fhall here infer t, viz. 

I diftilled a calculus in the iron retort 
(Fig. 38.) ; it weighed 230 grains, it was 
fomeihing lefs in bulk than | of a cubick 
inch : There arofe from it very briskly, in 
diftillation, 516 cubick inches of elaftick air, 
that is, a bulk equal to 645 times the bulk 
of the ftone -, fo that above half the ftone 
was raifed by the adtion of the fire into ela- 
ftick air > which is a much greater propor- 
tion of air than I have ever obtained by 
fire from any other fubftances, whether ani- 
mal, vegetable or mineral. The remaining 
calx weighed 49 grains, that is, ^-^ part 
of the calculus ; which is nearly the fame 
proportion of calx, that the worthy Dr. Slave 
found remaining, after the diftilling and cal- 
cining two ounces of calculus \ " one ounce 
u and three drams of which (he fays) eva- 
porated in the open fire, (a material cir- 
cumftance, which the chymifts rarely in- 
quire after) of which we have no account." 
Philof. Tra?7faB. Lowthorp's Abridgment, Vol. 
III. p. 179. The greateft part of which was, 
we fee by the prefent Experiment, raifed into 

permanently elaftick air. 




Analyfis of the Ah. \ 9 5 

By comparing this diftillation of the cal- 
culus with that of Renijh Tartar \ in Expe- 
riment 73, we fee that they both afford more 
air in diftillation, than any other fubftances : 
And it is remarkable, that a greater propor- 
tion of this new raifed air from thefe two 
fubftances, is reforbed, and lofes its elafti- 
city, in ftanding a few days, than that of any 
other bodies; which are ftrong fymptoms 
that the calculus is a true animal Tartar* 
And as there was very confiderably lefs oil, 
in the diftillation of Renijh Tartar, than 
there was in the diftillation of the feeds and 
folid parts of vegetables ; fo I found that 
this calculus contained much lefs oil than 
the blood or folid parts of animals. 

I diftilled in the fame manner as the above- 
mentioned calculus, fome ftones taken out 
of a human gall bladder j they weighed fifty- 
two grains, fo their bulk was equal to .i part 
of a cubick inch, as I found by taking their 
fpecifick gravity. There were 108 cubick 
inches of elaftick air raifed from them in 
diftillation, a quantity equal to 648 times 
their bulk; much the fame quantity that 
was raifed from the calculus, About i. part 
of this elaftick air was in four days reduced 
into a fix'd ftate, There arofe much morq 

O 2 oi 

i p 6 Analyfis of the An. 

oil in the diftillation of thefe Scones, than 
from the calculus, part of which oil did 
arife from the gall, which adhered to and 
was dried on the furfaces of the ftones.; 
which oil formed large bubbles, like thofe 
which arofe in the diftillation of Deers- 
horn, p. 193. 

A fmall ftone of the gall bladder, which 
was as big as a Pea, was diffolved in a Li- 
xivium of Sal Tartar in feven days, which 
Lixivium will alfo diffolve Tartar-, yet it 
will not diffolve the calculus, which is more 
firmly , united in its parts. 

A quantity of calculus equal to one half 
of what was diftilled, viz. 115 grains, did, 
when a cubick inch of fpiric of nitre was 
poured on it, diffolve in 2 or 3 hours, with 
a large froth, and generated 48 cubick inches 
of air, none of which loft its elafticity, tho' 
it flood many days in the glafs veffel. (Fig. 
34.). And a like quantity of Tartar being 
mixed with fpirit of nitre, was in the fame 
time diffolved ; but no elaftick air was gene- 
rated, notwithftanding Tartar abounds fo 
much with air. 

Small pieces of Tartar and Calculus were 
in 12 or 14 days both diffolved by oil of 
Vitriol y the like pieces of Tartar and Cal- 

Analyfis of the An. \ <)j 

cuius were diffolved in a few hours by oil of 
Vitriol, into which there was gradually poured 
near an equal quantity of fpirit of Harts- 
horn, made with Lime, which caufed a cons- 
iderable ebullition and heat. 

Tho' the remaining calx of the diftillation 
of Tartar, in Experiment 73. run per deli- 
quiu?n, and had therefore Sal Tartar in it > 
and tho* the calx of the diftilled Calculus did 
not run per deliquium, and had confequently 
no Sal Tartar in it ; yet it cannot thence 
be inferred, that the Calculus is not a tar- 
tarine fubftance : Becaufe by Experiment 74. 
it is evident, that Sal Tartar itfelf, when 
mixed w T ith an animal calx, diftils all over, 
fo that the calx will not afterwards run per 

By the great fimilitude there is therefore 
in fo many refpe&s between thefe two fub- 
ftances, we may well look upon the Calculus, 
and the Stone in the Gall Bladder, as true 
animal Tartars ; and doubtlefs Gouty concre- 
tions are the fame. 

From the great quantities of Air that are 
found in thefe Tartars, we fee that unela- 
flick Air particles, which by their ftrongly 
attracting property are fo inftrumental in form- 
ing the nutritive matter of Animals and Ve- 
O 3 getables, 

i p 8 Analyfis of the Air. 

getables, are by the fame attractive power apt 
fometimes to form anomalous concretions, 
as the Stone, &c. in Animals, efpccially in 
thofe places where any animal fluids are in 
a ftagnant ftate, as in the Urine and Gail- 
Bladders ' y they ftrongly adhere alfo to the 
fides of Urinals, ©V. The like tartarine con- 
cretions are alfo frequently formed in fome 
fruits, particularly in Pears ; but they do then 
efpecially coalefce in greateft plenty, when 
the vegetable juices are in a ftagnant ftate, as 
in wine veffels, &c. 

This great quantity of ftrongly attra&ing, 
unelaftick Air particles, which we find in the 
calculus, {hould rather encourage than dif- 
courage us, in fearching after fome proper 
diffolvent of the Stone in the Bladder, which, 
upon the Analyfis of ir, is found to be well 
ftored with adtive principles, fuch as are the 
principal agents in fermentation. For Mr. 
Boyle found therein a good quantity of vola- 
tile fait, with fome oil ; and we fee by the 
prefent Experiment, that there is ftore of 
unelaftick Air particles in it. The difficulty 
feems chiefly to lie, in the over-proportion 
of thefe laft-mentioned particles, which are 
firmly united together by fulphur and fait; 


Anal)Jis of the Ah. 1 9 9 

the proportion of caput moriuum, or earth, 
bekig very fmall. Vide Vol. II. p. 189. 

Experiment LXXVIII. 

One eighth of a cubick inch of Mercury 
made a very infenfible expanfion in diftilla- 
tion, notwithftanding the iron retort had an 
almoft melting heat given it at a fmith's forge, 
fo that it made an ebullition, which could be 
heard at fome diftance, and withal fhook the 
retort and receiver. There was no Air gene- 
rated, nor was there any expanfion of Air in 
the following Exper. viz. 

Experiment LXXIX. 

I put into the fame retort half a cubick 
Inch of Mercury, affixing to the retort a very 
capacious receiver, which had no hole in the 
bottom. The wide mouth of the receiver 
was adapted to the fmall neck of the retort 
(which was made of a mufket barrel) by means 
of two large pieces of cork,which entered and 
filled the mouth of the receiver, they having 
holes bored in them of a fit fize for the neck 
of the retort; and the jundlure was farther 
fecured, by a dry fupple bladder tied over it • 
O 4 for 

2 oo Analyfn of the Air. 

for I purpofely avoided making ufe of any 
moift lute, and took care to wipe the infide 
of the receiver very dry with a warm cloth. 

The Mercury made a great ebullition, and 
came fomc of it over into the receiver, as foon 
as the retort had a red heat given it, which 
was increafed to a white and almoft melting 
hear, in which ftate it continued for half an 
hour. During which time, I frequently co- 
hobated fome part of the Mercury which 
condenfed, and was lodged on an horizontal 
level, about the middle of the neck of the 
reron : And which, upon raifing the receiver, 
flowed down into the bottom of the retort, and 
there made a frefh ebullition \ which had 
ceafed, when all the Mercury was diflilled 
from the bottom of the retort. When all 
was cool, I found about two drams of Mercury 
in the retort, and loft in the whole forty-three 
grains, but there was not the leaft moiflure in 
the receiver-. 

Whence it is to be fufpected that Mr. Boyle 
and others were deceived by fome unheeded 
circumftance, when they thought they ob- 
tained a water from Mercury in the diflilla- 
tion of it 5 which he fays he did once, but 
could not make the like Experiment after- 
wards fucceed. Boyle, Vol. III. p. 416. 

I re 

Jnalyfis of the Air. i o i 

I remember that about twenty years fince, I 
was concerned with feveral others in making 
this Experiment at the Elaboratory in Trinity 
College Cambridge ; when imagining there 
would be a very great expanfion, we luted a 
German earthen retort to three or four large 
Alodals, and a capacious receiver; as Mr. 
WUfon did in his courfe of chymiftry. Four 
pounds of Mercury were poured by little and 
little into the red hot retort, thro' a tobacco- 
pipe purpofely affixed to it. The event was, 
that we fpund fome fpoons full of water with 
the Mercury in the Alodals, which I then fuf- 
pedted to arife from the moifture of the earthen 
retort and lute, and am now confirmed in 
that fufpicion. It rained inceflantly all the 
day, when I made this prefent Experiment 5 
fo that, when water is obtained in the diflil- 
lation of Mercury^ it cannot be owing to a 
moifler temperature of the Air. 

The Effecls of Fermentation on the Air. 
See Vol. II. page 295. 

HAving from the foregoing Experiments 
feen very evident proof of the produc- 
tion of confiderable quantities of true elaflick 
Air, from liquors and folid bodies, by means 


202 Analyjis of the Air. 

of fire ; we fliall find in the following Expc-r 
riments many inftances of the production, 
and alfo of the fixing or abforbing of great 
quantities of Air, by the fermentation arifing 
from the mixture of variety of folids and fluids: 
Which method of producing and of abforbing, 
and fixing the elaftick particles of Air by fer- 
mentation, feems to be more according to 
nature's ufual way of proceeding, than the 
other of fire. 

Experiment LXXX. 

I put into the bolthcad b (Fig. 34.) fixteen 
cubick inches of Sheep's blood, with a little 
water to make it ferment the better. I found 
by the defcent of the water from z to y, that 
in eighteen days fourteen cubick inches of Air 
were generated. 

Experiment LXXXL 

Volatile Salt of Sal Ammoniac > placed in aa 
open glafs ciftern, under the inverted glafs 
z z a a, (Fig. 35.) neither generated nor ab- 
forbed Air. Neither did feveral other vola- 
tile liquors, as fpirits of Harts-horn, fpirits of 
Wine, nor compound Aquafortis, generate 


Analyjls of the AW. 105 

any Air. But Sal Ammoniac, Sal -Tartar, 
and fpirits of Wine mixed together, generated 
twenty-fix cubick inches of Air, two of which 
were in four days reforbed, and after that ge- 
nerated again. 

Experiment LXXXII. 

Haifa cubick inch of Sal Ammoniac, and 
double that quantity of Oil oi Vitriol, gene- 
rated the firft day 5 or 6 cubick inches: But 
the following days it abforbed 15 cubick inches, 
and continued many days in that ftate. 

Equal quantities of fpirit of Turpentine, 
and Oil of Vitriol, had near the fame effedt, 
except that it was fooner in an abforbing ftate 
than the other. 

Mr. Geoffroy fhews, that the mixture of 
any vitriolic fairs, with inflammable fubftan- 
ces, will yield common Brimftone; and by 
the different compolitions he has made of 
fulphur, and particularly from Oil of Vitriol, 
and Oil of Turpentine, and by the Analyfis 
thereof, when thus prepared, he difcovered 
it to be nothing but vitriolic fait, united with 
the combuftibie fubftance. French Memoirs, 
Anno 1704. p. 381. or Boyle's Works, Vol 
III. p. 273. Notes. 


204 Analyfis of the Air. 

Experiment LXXXIII. 

In February I poured on fix cubick inches 
of powdered Oyfter-Jloell, an equal quantity of 
common white-wine Vinegar. In five or fix 
minutes it generated feventeen cubick inches 
of Air, and in fome hours twelve cubick inches 
more ; in all twenty-nine inches. In nine 
days it had llowly reforbed 2 1 cubick inches 
of Air. The ninth day I poured warm water 
into the veflel x x> (Fig. 34.) and the follow- 
ing day, when all was cool, I found (hat it 
had reforbed the remaining eight cubick inches. 
Hence we fee, that warmth will fometimes 
promote a reforbing as well as a generating 
ftate, viz. by raifing the reforbing fumes, as 
will appear more hereafter. 

Half a cubick inch of Oyfter-Jhell, and a 
cubick inch of 0/7 of Vitriol, generated thirty- 
two cubick inches of Air. 

Oyjlerfoell, and two cubick inches of four 
Rennet, of a Calf's ftomach, generated in 
four days, eleven cubick inches, But Oyjier- 
JJpell with fome of the liquor of a Calf's fto- 
mach, which had fed much upon Hay, did 
not generate air. It. was the fame vrithOv/ler - 
Jhell and Ox-gall, Urine and Spittle. 


Analyfis of the Air. 205 
Half a cubick inch oWyJler-fielUn&Sevil 
Orange juice generated the firft day thirteen 
cubick inches of Air, and the following days 
it reforbed that, and three or four more cu- 
bick inches of Air, and would fometimes 
generate again. It was the fame with Limon 

x Oyjlerfiell and Milk generated a little Air : 
But Limon juice and M/7/£did at the fame time 
abforb a little Air ; as did alfo Calves Rennet 
and Vinegar ; fome of the fame Rennet alone 
generated a little Air, and reforbed it again the 
following day. It had the fame eftedt when 
mixed with crums of bread. 

Experiment LXXXIV. 

A cubick inch of Limonjuice, and near an 
equal quantity of fpirifs of Harts-horn, perfe, 
i. e. not made with Lime, did in four hours 
abforb three or four cubick inches of Air j 
and the following day it remitted or generated 
two cubick inches of Air: The third day; 
turning from very warm to cold, it again re- 
forbed that Air, and continued in an abforb- 
ing flate for a day or two. 

That there is great plenty of Air incorpo- 
rated into the fubftanceof Vegetable's, which 


io6 Analyjis of the Air. 

by the a&ion of fermentation is rouzed into 
an elaftick ftate, is evident by thefe following 
Experiments, viz. 

Experiment LXXXV. 

March the fecond I poured into the bolt- 
head b (Fig. 34.) forty-two cubitk inches of 
Ale from the tun, which had been there fet 
to ferment thirty-four hours before: From 
that time to the ninth of "June it generated 63 9 
cubick inches of Air, with a very unequal 
progreffion, more or lefs as the weather was 
warm, cool, or cold j and fometimes, upon a 
change from warm to cool, it reforbed Air, 
in all thirty-two cubick inches^ 

Experiment LXXXVI. 

March the fecond, tw r elve cubick inches of 
Malaga Raifins, with eighteen cubick inches 
of water, generated by the 1 6th of April 411 
cubick indies of Air ; and then in two or three 
cold days it reforbed thirty-five cubick inches. 
From the 2 ift of April to the 16th of May it 
generated 78 cubick inches; after which to 
the 9th of June it continued in a reforbing 
ftate, fo as to reforb 13 cubick inches -, there 


Analyjis of the Air. 1 07 

were at this feafon many hot days, with much 
thunder and lightning, which deftroys the Airs 
elafticity; fo there were generated in all 489 
cubick inches, of which 48 were reforbed. 
The liquor was at laft very vapid. 

From the great quantity of Air generated 
from Apples, in the following Experiment, 'tis 
probable, that much more Air would have 
rifen from the laxer texture of ripe undried 
Grapes, than did from thefe Raifins. 

We fee from thefe Experiments on Raifins 
and Ale, that in warm weather Wine and Ale 
do not turn vapid by imbibing Air, but by fer- 
menting and generating too much, whereby 
they are deprived of their enlivening principle, 
the Air; for which reafon thefe liquors are 
beft preferved in cool cellars, whereby this 
a&ive invigorating principle is kept within due 
bounds, which when they exceed, Wines are 
upon the fret and in danger of being fpoiled. 

Experiment LXXXVII. 

Twenty-fix cubick inches of Apples being 
mzftied Augujl 10, they did in thirteen days 
generate 968 cubick inches of Air, a quantity 
equal to 48 times their bulk ; after which they 
did in three or four days reforb a quantity equal 


t o 8 Analyfts of the Air. 

to their bulk, notwithftanding it was very 
hot weather ; after which they were ftatio- 
nary, neither reforbing nor generating Air in 
many days. 

A very coarfe Brown-fugar, with an equal 
quantity of water, generated nine times its 
bulk of Air; Rice-four fix times its bulk; 
Scurvy-grafs leaves generated and abforbed 
Air; Peas, Wheat and Barley did in Fer- 
mentation alfo generate great quantities of 

That this Air, which arifes in fuch great 
quantities from fermenting and dhTolving 
vegetables, is true permanent Air, is certain, 
by its continuing in the fame expanded elaftick 
ftate for many weeks and months; which ex- 
panding watry vapours will not do, but foon 
condenfe when cool. And that this new gene- 
rated Air is elaftical, is plain, not only by its 
dilating and contracting with heat and cold, 
as common Air does, but alfo by its being 
compreffible, in proportion to the incumbent 
weight, as appears by the two following Ex- 
periments, which fhew what the great force 
of thefe aerial particles is, at the inftant they 
cfcape from the fermenting vegetables. 

E X P E- 

Analyjis of the Air. 209 

Experiment LXXXVIII. 

I filled the ftrong Hungary-water Bottle I? c 
(Fig, 3 6.) near half full of Peas, and then full 
of water, pouring in, firft, half an inch depth 
of Mercury ; then I fcrewed at b into the 
bottle the long {lender tube a z, which reached 
down to the bottom of the bottle ; the water 
was in two or three days all imbibed by the 
Peas, and they thereby much dilated ; the 
Mercury was alfo forced up the flender glafs 
tube near eighty inches high ; in which ftate 
the new generated air in the bottle was com- 
prefled with a force equal to more than two 
atmofpheres and an half $ if the bottle and 
tube were fvvung to and fro, the Mercury 
would make long vibrations in the tube be- 
tween z and 6 S which proves the great elafti- 
city of the compreffed air in the bottle. 

Exp eriment LXXXIX. 

I found the like elaftick force by the fol- 
lowing Experiment, viz. I provided a ftrong 
iron pota&cd, (Fig. 37.) which was two and 
3. inches diameter within fide, and five inches 
deep. I poured into it half an inch depth of 

P Mercury j 

2 1 o Jnaly/is of the Ait. 
Mercury; then I put a little coloured honey 
at x, into the bottom of the glafs-tube z x y 
which was fealed at the top. I fet this tube 
in the iron cylinder n n, to fave it from break- 
ing by the fwelling of the Peas. The pot 
being filled with Peas and water, I put a lea- 
thern collar between the mouth and lid of the 
pot, which were both ground even, and then 
preffed the lid hard down in a Cyder-prefs: 
The third day I opened the pot, and found 
all the water imbibed by the Peas; the Honey 
was forced up the glafs-tube by the Mercury 
to z y (for fo far the glafs was dawbed) by 
which means I found the preflure had been 
equal to two atmofpheres and ' y and the dia- 
meter of the pot being two -{- -| inches, its 
area was fix fquare inches, whence the dilate- 
ing iorce of the air againft the- lid of the pot 
was equal to 200 pounds. 

And that the expanfive force of new gene- 
rated air is vaftly fuperior to the power with 
which it acted on the Mercury in thefe two 
Experiments, is plain from the force with 
which fermenting Muft will burfl the ftrongefl 
veffels ; and from the vaft explofive force with 
which the air generated from nitre in the 
firing of gun-powder, will burlt afunder the 


Analyfis of the Air. 1 1 1 

ftrongeft bombs or cannon, and whirl fortifi- 
cations in the air. 

This fort of mercurial gage, made ufe of 
in Experiment #9, with fome un&uous mat- 
ter, as Treacle, or the like tinged liquor, 
on the Mercury in the tube, to note how 
high it rifes there, might probably be of fer- 
vice, in finding out unfathomable depths of 
the fea, viz. by fixing this fea-gage to fome 
buoyant body, which (hould be funk by a 
weight fix'd to it, which weight might by 
an eafy contrivance be detached from the 
buoyant body, as foon as it touched the bot- 
tom of the fea ; fo that the buoyant body 
and gage would immediately afcend to the 
furface of the water. The buoyant body ought 
to be pretty large, and much lighter than the 
water, that by its greater eminence above the 
water it might the better be feen ; for 'tis 
probable that from great depths it may rife 
at a confiderable diftance from the {hip, tho* 
in a calm. 

For greater accuracy it will be needful, 
firft, to try this fea-gage, at feveral different 
depths, down to the greateft depth that a 
line will reach, thereby to difcover, whe- 
ther or how much the fpring of the air is 
difturbed or condenfed, not only by the great 
P 2 preflure 

2 1 1 Analyfts of the Jir. 

preflure of the incumbent water, but alfo by 
its coldnefs at great depths; and in what pro- 
portion, at different known depths, and in 
different lengths of time, that an allowance 
may accordingly be made for it at unfatho- 
mable depths. See Vol. II. p. 332. 

This gage will alfo readily ihew the de- 
grees of compreffion in the condenfing en- 

But to return to the fubjedt of the two laft 
Experiments, which prove the elafticity of 
this new generated air; which elafticity is 
fuppofed to confift in the adtive aerial par- 
ticles, repelling each other with a force, 
which is reciprocally proportional to their 
diftances: That illuftrious Philofopher, Sir 
Ifaac Newton, in accounting how air and 
vapour is produced, Opticks g*uer. 31. fays, 
" The particles, when they are fhaken off 
" from bodies by heat or fermentation, fo 
" foon as they are beyond the reach of the 
l< attraction of the body receding from it, 
" as alfo from one another, with great ftrength 
" and keeping at a diftance, fo as ibmetimes 
<l to take up above a million of times more 
" fpace than they did before in the form of 
" a denfe body ; which vaft contraction and 
< c expanfion feems unintelligible, by feign- 

* ing 

AnaJyJts of the Air. 1 1 3 

Ci ing the particles of air to be fpringy and 
M ramous, or rolled up like hoop?, or by any 
<c other means than by a repulfive power." 
The truth of which is further confirmed by 
thefe Experiments, which mew the great 
quantity of air emitted from fermenting bo- 
dies ; which not only proves the great force 
with which the parts of thofe bodies muft 
be diftended ; but (hews alfo how very much 
the particles of air muft be coiled up in that 
ftate, if they are, as has been fuppofed, fpringy 
and ramous. 

To inftance in the cafe of the pounded 
Apples, which generated above 48 times 
their bulk of air ; this air, when in the 
Apples, mud be compreffed into lefs than 
a forty-eighth part of the fpace it takes up 
when freed from them, and it will confe- 
quently be forty-eight times more denfe \ 
and fince the force of compreffed air is pro- 
portional to its denfity, that force which 
compreffes and confines this air in the Ap- 
ples, mud be equal to the weight of forty- 
eight of our atmofpheres, when the Mer- 
cury in the Barometer ftands at fair, that is, 
30 inches high, 

P 3 Now 

1 1 4 Analyjis of the Air. 

Now a cubick ineh of Mercury weighing 
3580 grains, thirty cubick inches (which is 
equal to the weight of our atmofphere on 
an area of a cubick inch) will weigh fifteen 
pounds, five ounces, 215 grains; and forty- 
eight of them will weigh above 836 pounds; 
which is therefore equal to the force with 
which an inch fquare of the furface of the 
Apple would comprefs the air, fuppofing 
there were no other fubflance but air in the 
Apple: And if we take the furface of an 
Apple at fixteen fquare inches, then the 
whole force with which that furface would 
comprefs the included air, would be 13383 
pounds. And fince action and reaction 
are equal, this would be the force, with 
which the air in ttif Apple would endea- 
vour to expand itfelf, if it were there in 
an elaflick and flrongly compreiTed ftate : 
But fo great an expanfive force in an Apple 
would certainly rend the fubflance of it with 
a ftrong explofion, efpecially when that force 
was increafed by the vigorous influence of 
the Sun's warmth. 

We mav make a like eflimate alfo, from 
the great quantities of air which arofe either 
by fermentation, or the force of fire from 
feveral other bodies. Thus in Exp. 55. there 


Anal)Jis of the Air. 1 1 J 

arofe from a piece of heart of Oak> 216 
times its bulk of air. Now 216 cubick 
inches of air, compreffed into the fpace of 
one cubick inch, would, if it continued there 
in an elaftick ftate, prefs againft one fide of 
the cubick inch with an expanfive force equal 
to 3393 pounds weight, fuppofing there were 
no other fubflance but air contained in its 
and it would prefs againft the fix fides of 
the cube, with a force equal to 20350 
pounds, a force fufHcient to rend the Oak 
with a vaft explofion: It is very reafonable 
therefore to conclude, that mod of thefe 
now adtive particles of the new generated 
air, were in a fixed ftate in the Apple and 
Oak before they were roufed, and put into 
an adlive repelling ftate, by fermentation and 

The weight of a cubick inch of Apple 
being 191 grains, the weight of a cubick 
inch of air f of a grain, forty-eight times 
that weight of air is nearly equal to the four- 
teenth part of the weight of the Apple. 

And if to the air thus generated from a 
vefiel cf any vegetable liquor by fermenta- 
tion, we add the air that might afterwards 
be obtained from it by heat or diftillation j 
and to that alfo the vaft quantity of air which 

P 4 by 

2 1 6 dnalyfis of the Jir. 

by Experiment 73 is found to be contained 
in its Tartar, which adheres to the fides of 
the veflel ; it would by this means be found 
that air makes a very confiderable part of 
the fubftance of Vegetables, as well as of 

But though from what has been faid, it 
is reafonable to think, that many of thefe 
panicles of air were in a fixed ftate, ftrongly 
adhering to, and wrought into the fubftance 
of Apples ; yet on the other hand it is rnoft 
evident from Exper. 34. and 38, where in- 
numerable bubbles of air inceffantly arofe 
through the fap of Vines, that there is a con~ 
fiderable quantity of air in Vegetables, upon 
the wing, and in a very a&fve ftate, efpeci- 
ally in warm weather, which inlarges the 
fphere of their adivity. 

7*he Eff'eEls of the Fermentation of mineral 
Subjlancis on the Air, 

I Have above fhewn that Air may be pro- 
duced from mineral Subftances, by the 
adtion of fire in diftillation. And we have, 
in the following Experiments, many inftances 
of the great plenty of air, which is generated 
by fome fermenting mixtures, ab r orbed by 


JnaJyfis of the Ah\ 2 1 7 

others, and by others alternately generated 
and abforbed. 

Experiment XC. 

I poured upon a middle-fized Gold Ring, 
beat into a thin plate, two cubick inches of 
Aqua Regia ; the Gold was all diffolved the 
next day, when I found four cubick inches 
of air generated ; for air-bubbles were conti- 
nually arifing during the folution : But fince 
Gold lofes nothing of its weight in being thus 
diffolved, the four cubick inches of air, which 
weighed more than a grain, muft arife either 
out of the pores of the Gold, or from the 
Aqua Regia ; which makes it probable, that 
there are air particles in acid fpirits ; for by 
Experiment feventy - five, they abforb air ; 
which air parjicles regained their elafticity, 
when the acid fpirits which adhered to them 
were more ftrongly attracted by the Gold, 
than by the air particles. 

Experiment XCI. 

A quarter pf a cubick inch of Antimony, 
and two cubick inches of Aqua Regia, gene- 
rated thirty-eight cubick inches of air, the 


1 1 & Analyfa of the Air. 

firft three or four hours, and then abforbed. 
fourteen cubicle inches in an hour or two. 
It is very obfervable, that air was generated 
while the ferment was fmall, on the firft mix- 
ing of the ingredients : But when the ferment 
was greatly increafed, fo that the fumes rofe 
very vifibly, then there was a change made 
from a generating to an abforbing ftate; that 
is, there was more aL abforbed than gene- 

That I might find whether the air was ab- 
forbed by the fumes only of the Aqua Regia, 
or by the acid fulphureous vapours, which 
afcended from the Antimony, I put a like 
quantity of Aqua Regia into a bolthead b> 
(Fig. 34.) and heated it, by pouring a large 
quantity of hot water into the ciftcrn x x y 
which flood in a larger veffel, that retained 
the hot water about it, but no air was ab- 
forbed 5 for when all was cold, the water 
ftoad at the point z y where I firft placed it : 
And I found it the fame, when, inftead of 
Aqua Regia, I put only fpirit of Nitre into 
the bolthead b- y yet in the diftillation of com- 
pound Aqua-fortis, Exper. 75. a little was ab- 
forbed. Hence therefore it is probable, that 
the greareft part, if not all the air, was ab- 
forbed by the fumes which arofe from the 
Antimony, E x- 

Analyfis of the Air. 1 1 9 

Experiment XCII. 
Some time in February, the weather very 
cold, I poured upon a quarter of a cubick 
inch of powdered Antimony, a cubick inch 
of compound or double Aqua-fortis, in the 
bolthead b (Fig. 34.) : in the firft 20 hours 
it generated about 8 cubick inches of air ; 
after that, the weather being fomewhat 
warmer, it fermented fafter, fo as in two or 
three hours to generate 82 cubick inches of 
air more ; but the following night being very 
cold, little was generated : So the next morn- 
ing I poured hot water into the veffel x x t 
which renewed the ferment, fo that it gene- 
rated 4 cubick inches more, in all 130 cubick 
inches, a quantity equal to 520 times the 
bulk of the Antimony. 

The fermented mais looked like Brim- 
ftone, and when heated over the fire, there 
fublimed into the neck of the boithead a red 
fulphur, and below it a yellow; which ful- 
p.hur, as Mr. Boyle obfecves, Vol. IIL ^.272. 
cannot be obtained by the, bare action of fire, 
without being firft well digefted ia oil o£ 
Vitriol, or fpirit of Nirre. And by com- 
paring the quantity of aix obtained by fermen- 
tation in this Experiment, with the quantity 


120 Analyfis of the Air. 

obtained by the force of fire in Exper. 69. 
we find that five times more air was generated 
by fermentation than by fire, which fhews 
fermentation to be a more fubtle diffolvent 
than fire ; yet in fome cafes there is more air 
generated by fire than by fermentation. 

Half a cubick inch of oil of Antimonw 
with an equal quantity of compound Aqua- 
fortis, generated 36 cubick inches ofelaftick 
air, which was all reforbed the following 

Expert me nt XCIII. 

Some time in February, a quarter of a 
cubick inch of filings of Iron, and a cubick 
inch of compound Aqua-fortis, without any 
water, did, in four days, abforb 27 cubick 
inches of air. It having ceafed to abforb, I 
poured hot water into the veffel * x, to try if 
I could renew the ferment. The effect of 
this was, that it generated three or four cu- 
bick inches of air, which continued in that 
ftate for fome days, and was then again re- 

1 repeated the fame Experiment in warm 
weather in April, when it more briskly ab- 
foiDed 12 cubick inches in an hour. 


Jnalyfis of the Air. 1 1 1 

Experiment XCIV. 

March 12th, - of a cubick inch of filings 
of Iron, with a cubick inch of compound 
Aqua-forth, and an equal quantity of water, 
for the firft half hour abforbed five or fix 
cubick inches of air; but in an hour more 
it had emitted that quantity of air; and in 
two hours more it again reforbed what had 
been juft befQre emitted. The day following 
it continued abforbing, in all 12 cubick in- 
ches: And then remained ftationary for j£ 
or 20 hours. The third day it had again re- 
mitted or generated three or four cubick 
inches of air, and thence continued ftationary 
for five or fix days. 

It is remarkable, that the fame mixtures 
fhould change from generating to abforbing, 
and from abforbing to generating flates ; fome- 
times with, and fometimes without any fen- 
fible alteration of the temperature of the air. 
See Vol. II. p. 237, 293. 

A like quantity of filings of Iron, and oil 
of Vitriol, made no fenfible ferment, and 
generated a very little air; but upon pouring 
in an equal quantity of water, it generated 
in 21 days 43 cubick inches of air; and in 3 
or 4 days more it reforbed 3 cubick inches of 


ill Aiialyfn of the Ah. 

air ; when the weather turned warmer, it was 
generated again* which was again reforbed 
when it grew cool. 

One fourth of a cubick inch of filings of 
Iron, and a cubick inch of oil of Vitriol, with 
three times its quantity of water, generated 
1 08 cubick inches of ain 

Filings of Iron, with fpirit of Nitre, either 
with an equal quantity of 'Water, or without 
water, abfojbed air, but moft without water. 

One fourth of a cubick inch of filings of 
Iron, and a cubick inch of Limon- juice, ab- 
forbed two cubick inches of air. 

Experiment XCV. 

Half a cubick inch otfpirits of Harts- 
horn, with filings of Iron, abforbed 1 -j- i. 
cubick inches of air, with filings of Copper, 
double that quantity of air, and made a very 
deep blue tin&ure, which it retained long, 
when expofed to the open air. It was the 
fame with Jpirit of Sal Armoniac, and filings 
of Copper. 

A quarter of a cubick inch of filings of 
Iron, with a cubick inch of powdered Brim- 
flone, made into a parte with a little water, 
abforbed 19 cubick inches of air in two days. 


Analyfis of the Air. 1 1 $ 

N B. I poured hot water into the ciftern xx, 
(Fig. 34.) to promote the ferment. 

A like quantity of filings of Iron, and pow- 
dered Newcajlle Coal, did in three or four 
days generate feven cubicle inches of air. I 
could not perceive any fenfible warmth in 
this mixture, as was in the mixture of Iron 
and Brimjione. 

Powdered Brimfione and Newcafile Coal 
neither generated nor abforbed. 

Filings of Iron and Water abforbed three 
or four cubick inches of air ; but they do not 
abforb fo much, whenimmerfed deep in wa- 
ter ; what they abforb isufualjy the firft three 
or four days. 

Filings of Iron, and the above-mentioned 
Walton Pyrites, in Exper. 70. abforbed in 
four days a quantity of air nearly equal to 
double their bulk. 

Copper Oar, and compound Aqua-fortis, 
neither generated nor abforbed air; but, mixed 
with water, it abforbed air. 

A quarter of a cubick inch of Tin, and 
double that quantity of compound Aqua-fort is y ^ 

t generated two cubick inches of air ; part of 
the Tin was diffolved into a very white fub- 


z 2 4 Analyjis of the Air. 

Experiment XCVI. 

April 1 6th, a cubick inch of the afore- 
mentioned Walton Pyrites powder'd, with a 
cubick inch of compound Aqua-fortis, expanded 
with great violence, heat and fume into a fpace 
equal to 200 cubick inches, and in a little time 
it condenfed into its former fpace, and then 
abforbed 85 cubick inches of air. 

But the like quantity of the fame Mineral, 
with equal quantities of compound Aqua-fort is 
and Water, fermented more violently, and ge- 
nerated above 80 cubick inches of air. 

I repeated thefe Experiments feveral times, 
both with and without water, and found con- 
ftantly the fame effect. Yet Oil of Vitriol 
and Water, with fome of the fame Mineral, 
abforbed air. It was very warm, but did not 
make a great ebullition. 

But this Walton Mineral, with equal quan- 
tities of fpirit of nitre and water, generated 
air, which air would abforb frefh admitted 
air. See Vol II. p. 283, 292. 

Experiment XCVII. 

I chofe two equal-fized boltheads, and 
put into each of them a cubick inch of 


Analyjis of the Air. 225 

powdered Walton Pyrites, with only a cu- 
bicle inch of compound Aqua-fortis into one, 
and a cubick inch of Water and compound 
Aqua-fortis into the other : Upon weighing 
all the ingredients and veflels exadtly, both 
before and after the fermentation, I found 
the bolthead with compound Aqua-fortis alone 
had loft in fumes 1 dram 5 grains : But the 
other bolthead with Water and compound 
Aqua-fortis, which fumed much more, had 
loft 7 drams, 1 fcruple, 7 grains, which is 
fix times as much as the other loft. 

Experiment XCVIIL 
A cubick inch of Newcajlle Coal pow- 
dered, and an equal quantity of compound 
Aquafortis poured on it, did in three days 
abforb 18 cubick inches of air; and in 3 
days more it remitted and generated 12 cu- 
bick inches of air; and on pouring warm 
Water into the veffel x x, (Fig. 34.) it re- 
mitted all that had been abforbed. 

Equal quantities of Brim/lone and com- 
pound Aqua-fortis neither generated nor ab- 
forbed any air, notwithstanding hot Water 
was poured into the veffel x x. 

A cubick inch of finely powdered Flint y 
and an equal quantity of compound Aqua- 

Q_ fortis, 

ix6 Analyfis of the Atr. 

fortis, abforbed in 5 or 6 days 12 cubick 
inches of air. 

Equal quantities of powdered Brijlol 
Diamond, and compound Aqua-fortis, and 
Water , abfored 16 times their bulk of air. 

The like quantities without Water ab- 
forbed more flowly 7 times their bulk of 

Powder'd Briftol Marble (viz. the fhell 
in which thofe Diamonds lay) covered pretty 
deep with Water, neither generated nor 
abforbed air ; and it is well known that 
Brijlol Water does not fparkle like fome 
other Mineral Waters, 

Experiment XCIX. 

When the Aqua Regia was poured on Oleum 
Tartari per deliquium, much air was gene- 
rated, and that probably chiefly from the 
Oleum Tartaric for by Exper. 74. Sal Tar- 
tar has plenty of air in it. 

It was the lame when the oil of Vitriol 
Wiis poured on &ieum 'Tartaric and Oleum 
Tartar! dropped on boiling Tartar generated 
much 2ir. 

When equal quantities of Water and oil* 
fcf Vitriol were poiwed on fea fait, it ab- 
forbed 15 cubick inches of air; but when 


Analyfts of the Air. 227 

in the like mixture the quantity of Water 
was double to that of the oil of Vitriol, 
then but half fo much air was abforbed. 

Experiment C. 

I will next mew, what effedt feveral Al- 
kaline Mineral bodies had on the air in fer- 
menting mixtures. 

A folid cubick inch of unpowdered Chalky 
with an equal quantity of oil of Vitriol^ fer- 
mented much at firft, and in fome degree 
for 3 days 5 they generated 31 cubick inches 
of air. The Chalk was only a little diflblved 
on its furface. 

One hundred and forty-fix grains, or near 
one third of a cubick inch of Chalky being 
let fall on two cubick inches of fpirit of 
fait, 8 1 cubick inches of air were generated, 
of which 36 cubes were reforbed in 9 days. 

Yet Lime made of the fame Chalk abforb- 
ed much air, when oil of Vitriol was poured 
on it; and the ferment was fo violent, that 
it breaking the glafs vefTels, I was obliged to 
put the ingredients in an Iron veiTel. 

Two cubick inches of frefh Lime, and 
four of common white wine Vinegar abforb- 
ed in 15 days 22 cubick inches of air. 

Q_2 The 

2 1 8 Analyfii of the Ait. 

The like quantity of frefh Lime and 
Water abforbed in 3 days 10 cubick inches 
of air. 

Two cubick inches of Lime, and an equal 
quantity of Sal Ammoniac ', abforbed 115 cu- 
bick inches: Tlie fumes of this mixture are 
therefore doubtlefs very fuffocating. 

A quart of unflacked Lime, left for 44 
days, to flacken gradually by it-felf, without 
any mixture, abforbed no air. 

March 3d, a cubick inch of powdered 
Belemnitis, taken from a Chalk pit, and an 
equal quantity of oil of Vitriol, generated 
in five minutes 35 cubick inches of air. 
March 5th, it had generated 70 more. 
March 6th, it being a hard froft, it reforb- 
ed 12 cubick inches ; fo it generated in all 
105 inches, and reforbed 12. 

Powdered Belemnitis and Limon juice ge- 
nerated plenty of air too; as did alfo the 
Star-jlone, Laps Judaicus, and Selenitis 
with oil of Vitriol. 

Eyperiment CI. 

Gravel, that is well burnt, Wood-ajhes, 
decrepitated Salt, and Colcothar of Vitriol, 
placed feverally under the inverted glafs 
zzaa, (Fig. 35.) increased in weight by 


Jnalyfis of the Air. 229 

imbibing the floating moifture of the air: 
But they abforbed no elaftick air. It was 
the fame with the remaining lixivious Salt 
of a diftillation of Nitre. 

But 4 or 5 cubick inches of powdered 
frefh Cinder of Newca/l/e Coal did in feven 
days abforb 5 cubick inches of elaftick air. 
And 13 cubick inches of air were in 5 days 
abforbed by Puhis Urem, a powder which 
immediately kindles into a live Cole, up- 
on being expofed to the open air. 

Experiment CII. 

What effect burning and flaming bodies, 
and the refpiration of Animals, have on the 
air, we fliall fee in the following Experi- 
ments ; viz. 

I fix'd upon the pedeftal under the in- 
verted glafs z z a a, (Fig. 35.) a piece of 
Brown Paper, which had been dipped in a 
fclution of Nitre, and then well dried; I 
fet fire to the Paper by means of a burn- 
ing-glafs: The Nitre detonized, and burnt 
briskly for ibme time, till the glafs z z a a 
was very full of thick fumes, which extin- 
guifhed it. The expanfion caufed by the 
burning Nitre, was equal to more than two 
quarts: When all was coo!, there were near 

Q 3 80 cu- 

2 3 o AnaJyfts of the AW. 

80 cubick inches of new generated air, which 
arofe from a fmall quantity of detonized 
Nitre ; but the elaflicity of this new air dai- 
ly decreafed, in the fame manner as Mr. 
Hawksbee obferved the air of fired Gun- 
powder to do, Phyfico-mechanical Exper. 
p. 83. fo that he found 19 of 20 parts occu- 
pied by this air to be deferted in 18 days, 
and its fpace filled by the afcending water; 
at which flation it relied, continuing there 
for 8 days without alteration : And in like 
manner, I found that a confiderable part of 
the air which was produced by fire in the 
diftillation of feveral fubftances, did gra- 
dually lofe its elaflicity in a few days after 
the diftillation was over ; but it was not fo 
when I diftilled air thro* water, as in Expe- 
riment 77. (Fig. 38. ) 

Experiment CHI. 

I placed on the fame pedeftal large Matches 
made of linen rags dipped in melted Brim- 
ftone: The capacity of the veflel, (Fig. 35.) 
above z z the furface of the water, was 
equal to 2024 cubick inches. The quantity 
pf air which was abforbed by the burning 
Match, was 198 cubick inches, equal to -$ 
part of the whole air in the vefle!. 

I made 

Analyfis of the Air. 2 5 1 

I made the fame Experiment in a leffer 
veffel z z a a, (Fig. 35.) which contained 
but 594 cubick inches of air, in which 150 
cubick inches were abforbed; /. e. full $ 
part of the whole air in the receiver: So 
that tho' more air is abforbed by burning 
Matches in large veffels, where they burn 
longeft, than in fmall ones, yet more air, 
in proportion to the bulk of the veffel, is 
abforbed in fmall than in large veffels : If a 
frefh Match were lighted and put into this 
infected air, tho' it would not burn i part 
of the time that the former Match burnt 
in frefh untainted air, yet it would abforb 
near as much air in that fhort time ; and it 
was the fame with Candles. 

Experiment CIV. 

Equal quantities of ^filings of Iron and 
Brim/lone, when let fall on a hot Iron on 
the pedeftal under the inverted glafs zz a a y 
(Fig. 35.) did in burning abforb much aif ; 
and it was the fame with Antimony and 
Brimjione : Whence 'tis probable, that Vul- 
cano's, whofe fewel confifts chiefly of Brim- 
jione, mix'd with feveral mineral and me- 
talline fubftances, do not generate, but ra- 
ther abforb air. 

CL4 We 

2 3 l Analyjis of the Ah. 

We find in the foregoing Experiment 102 
on Nitre, that a great part of the new ge- 
nerated air is in a few days reforbed, or 
loies its elafticity: But the air which is ab- 
forbed by burning Brimjiofte, or the flame 
of a Candle, does not recover its elafticity 
again, at leaft, not while confined in my 

Experiment CV. 
I made feveral attempts to try whether 
air full of the fumes of burning Brim/lone 
was as compreffible as common frefh air, 
by compreffing at the fame time tubes full 
of each of thefe airs in the condenfing en- 
gine y and I found that clear air is very lit- 
tle more compreffible than air with fumes 
of Brimjione in it : But I could not come to 
an exa£t certainty in the matter, becaufe the 
fumes were at the fame time deftroying the 
elafticity of the air. I took care to make 
the air in both tubes cf the fame tempera- 
ture, by firft immerfing them in cold water, 
before I compreffed them. See appendix 
Vol II. p. 319, 320. 

Experiment C VI. 
I let a lighted tallow Candle, which was 
about -/-- of an inch diameter, under the in- 

Analysis of the* Air. 1 3 5 
verted receiver zzaa, (Fig. 35. ) and with 
a fyphon I immediately drew the water up 
to z z : Then drawing out the fyphon, the 
water would defcend for a quarter of a mi- 
nute, and after that afcend, notwithftand- 
ing the Candle continued burning, and heat- 
ing the air for near 3 minutes. It was ob- 
fervable in this Experiment, that the fur- 
face of the water z z did not afcend with 
an equal progreffi.on, but would be fome- 
times ftationary ; and it would fometimes 
move with a flow, and fometimes with an 
accelerated motion; but the denfer the fumer, 
the fafter it afcended. As foon as the Can- 
dle was out, 1 marked the height of the 
water above z z, which difference was 
equal to the quantity of air, whofe elafti- 
city was deftroyed by the burning Candle. 
As the air cooled and condenfed in the re- 
ceiver, the water would continue riling 
above the mark, not only till all was cool, 
but for 20 or 30 hours after that, which 
height it kept, tho' it flood many days; 
which fhews that the air did not recover the 
elafticity which it had loft. 

The event was the fame, when for great- 
er accuracy I repeated this Experiment by 
lighting the Candle after it was placed un- 

234 Analyfis of the Ah. 

der the receiver, by means of a burning-glais, 
which fet fire to a fmall piece of brown pa- 
per fixed to the wick of a Candle, which 
paper had been firft dipped in a ftrong folu- 
tion of Nitre in Water; and when well 
dried, part of it was dipped in melted Brim- 
fione ; it will alfo light the Candle without 
being dipped in Brim/lone. Dr. Mayow, 
found the bulk of the air lefTened by -fa part, 
but does not mention the fize of the glafs 
vefTel under which he put the lighted Can- 
dle, ^De Sp. Nitro aereo^ p. 101. The capa- 
city of the vefTel above z z, in which the 
Candle burnt in my Experiment, was equal 
to 2024 cubick inches; and the elafticity of 
the ~\ part of this air was deftroyed. 

The Candle cannot be lighted again in 
this infected air by a burning-glafs: But if 
I firft lighted it, and then put it into the 
fame infe&ed air, tho' it was extinguished 
in - part of the time, that it would burn in 
the fame vefTel, full of frefh air; yet it 
would deftroy the elafticity of near as much 
air in that fhort time, as it did in five times 
that fpace of time in frefh air; this I re- 
peated feveral times, and found the fame 
event : Hence a grofs air, which is loaded 
wivh vapours, is more apt in equal times to 


Analyfis of the AW. 235 

lofe its elafticity in greater quantities, than 
a clear air. 

I obferve that where the vefTels are equal, 
and the fize of the Candles unequal, the 
elafticity of more air will be deftroyed by 
the large than by the fmall Candle : and where 
Candles are equal, there moft air in propor- 
tion to the bulk of the veffel will be ab- 
forbed in the fmalleft veffel : tho' with 
equal Candles there is always moft elaftick: 
air deftroyed in the largeft veffa], where the 
Candle burns longeft. 

I found alfo in fermenting liquors, that, 
Ceteris paribus, more air was either gene- 
rated or abforbed in large, than in fmajl 
veffels, by generating or abforbing mixtures. 
As in the mixture of Aqua Regia and Antl* 
mony in Experiment 91. by inlarging thea 
bulk of the air in the veffel, a greater quan- 
tity of air was abforbed. Thus alfo filings 
of Iron and Brimjtone, which in a more capa- 
cious veffel abforbed 19 cubick inches of 
air, abforbed very little, when the bulk of 
air, above the ingredients, was but 3 or 4 
cubick inches: For I have often obferved, 
that when any quantity of air is faturated 
with abforbing vapours to a certain degree, 
then no more elaftick air is abforbed: Not- 


1^6 Analyjis of the Aif. 

withftanding the fame quantity of abforbing 
fubftances would, in a larger quantity of air, 
have abforhed much more air; and this is 
the reafon why I was never able to deflroy 
the whole elafticity of any ineiudcd bulk of 
air, whether it was (common air, or new 
generated air. 

Experiment CVII. 

May 1 8. which was a very hot day, I 
repeated Dr. Mayow's Experiment, to find 
how much air is abforbed by the breath of 
Animals inclofed in glaffes, which he found 
with a moufe to be T ' T part of the whole 
air in the glafs vefTel, JDe Sp. Nitro aereo, 
p. 104. 

I placed on the pedeftal, under the invert- 
ed glafs zz a a, (Fig. 35. ) a full-grown 
Rat. At firft the water fubfided a little, 
which was occalioned by the rarefa&ion of 
the air, caufed by the heat of the animal's 
body. But after a few minutes the water be- 
gan to rife, and continued riling as long 
as the Rat lived, which was about 14 hours. 
The bulk of the air in which the Rat 
lived fo many hours, was 2024 cubick inches; 
the quantity of elaftick air which was ab- 
forbed, was 73 cubick inches, above yf part 


Analyfn of the Air. 237 

of the whole, nearly what was abforbed 
by a Candle in the fame veffel, in Experi- 
ment 106. 

I placed at the fame time, in the fame 

manner, another almoft half-grown Rat 
under a veffel, whofe capacity above the 
furface of the water z z> (Fig. 35.) was bus 
594 cubick inches, in which it lived 10 
hours ; the quantity of elaftick air which 
was abforbed, was equal to 45 cubick 
inches, viz. ri P art °f tne wn °l e air, which 
the Rat breathed in : A Cat of three months 
old lived an hour in the fame receiver, 
and abforbed 16 cubick inches of air, 
viz. -3% part of the whole j an allowance 
being made in this eftimate for the bulk of 
the Cat's body. A Candle in the fame veffel 
continued burning but one minute, and ab- 
forbed 54 cubick inches, T V part of the 
whole air. 

And as in the cafe of burning Brim/lone 
and Candles, more air was found to be ab- 
forbed in large veffels than in fmall ones ; 
and vice verfa, more air, in proportion to the 
capacity of the veffel, was abforbed in fmall 
than in large veffels, fo the fame holds true 
here too in the cafe of animals. 


138 Analyfis of the Mr. 

Experiment CVIII. 

The following Experiment will (hew, 
that the elaflicity of the air is greatly de- 
ftroyed by the refpiration of human Lungs - 3 

I made a bladder very fupple by wetting 
of it, and then cut off fo much of the neck 
as would make a hole wide enough for the 
biggeft end of the largeft foffet to enter, to 
which the bladder was bound faft. The 
bladder and foffet contained 74 cubicle 
inches. Having blown up the bladder, I 
put the fmall end of the foffet into my 
mouth ; and at the fame time pinched my 
noftrils clofe, that no air might pafs that 
way, fo that I could only breath to and fro 
the air contained in the bladder. In lefs 
than half a minute I found a confiderable 
difficulty in breathing, and was forced after 
that to fetch my breath very faft; and at 
the end of the minute, the fuffocating un- 
eafinefs was fo great, that I was forced to 
take away the bladder from my mouth. 
Towards the end of the minute the blad- 
der was become fo flaccid, that I could not 
blow it above half full with the greateft 
expiration that I could make : And at the 


Analyjis of the Ait . ity 

fame time I could plainly perceive, that my 
lungs were much fallen, juft in the fame 
manner as when we breath out of them 
all the air we can at once. Whence it is 
plain that a confiderable quantity of the 
elafticicy of the air contained in my lungs, 
and in the bladder, was deftroyed; which 
fuppofing it to be 20 cubick inches, it will 
be T ' part of the whole air, which I breath- 
ed to and fro; for the bladder contained 
74 cubick inches, and the lungs, by the 
following Experiment, about 166 cubick 
inches, in all 240. 

Thefe effects of refpiration on the ela- 

rfticity of the air put me upon making an 
attempt to meafure the inward furface of 
the lungs, which by a wonderful artifice 
are admirably contrived by the divine Ar- 
tificer, fo as to make their inward furface 
to be commenfurate to an expanfe of air 
many times greater than the animal's body; 
as will appear from the following efiimate 


Experiment CDC 

I took the lungs of a Calf, and cut off 
the heart and wind-pipe an inch above its 
branching into the lungs j I got nearly the 


140 Analyfis of the Air. 
fpecifick gravity of the fubftance of the 
lungs, (which is a continuation of the branch- 
ii es of the wind-pipe, and blood- vefiels) by 
finding the fpecifick gravity of the wind- 
pipe, which I had cut off; it was to Well- 
water as 1.05 to 1. And a cubick inch of 
water weighing 254 grains; I thence found 
by weighing the lungs the whole of their 
folid fubftance to be equal to 37 +~ cubick 

I then filled a large earthen veflel brim- 
full of water, and put the lungs in, which 
I blew up, keeping them under water with 
a pewter plate. Then taking the lungs out, 
and letting the plate drop to the bottom of 
the water, I poured in a known quantity of 
water, till the vefTel was brim-full again; that 
water was 7 pounds 6 ounces and \ y equal 
to 204 cubick inches; from which deduct- 
ing the fpace occupied [by the folid fubftance 
of the lungs, viz. 37 +? cubick inches, 
there remains 166 -j- 7 cubick inches for 
the cavity of the lungs. But as the Pul- 
monary Veins, Arteries and Lymphaticks, 
will, when they are in a natural ftate, re- 
plete with blood and lymph, occupy more 
fpace than they do in their prefent empty 
ftate; therefore fome allowance muft alfo 


Analyjis of the Air. 241 

be made out of the above taken cavity of 
the lungs, for the bulk of thofe fluids ; for 
which 25 + i. cubick inches feem to be a 
fufficient proportion, out of the 166 + \ cu- 
bick inches 5 fo there remain 141 cubick 
inches for the cavity of the lungs. 

I poured as much water into the BrGtichia 
as they would take in, which was one pound 
eight ounces, equal to 41 cubick inches; 
this deducted from the above-found cavity 
of the lungs, there remain 100 cubick 
inches for the fum of the cavity of the 

Upon viewing fome of thefe veficles with 
a microfcope, a middle-fized one feems to 
be about -^- part of an inch diameter ; then 
the fum of the furfaces in a cubick inch of 
thefe fmall veficles (fuppofing them to be 
fo many little cubes, for they are not fphe- 
rical) will be 600 fquare inches -, for if the 
number of the divifions of the fide of the 
cubick inch be 100, there will be 100 
planes, containing each one fquare inch, in 
each dimenfion of the cube ; which having 
three dimenfions, the fum of thofe planes 
will be 300 fquare inches, and the fum of 
the furfaces of each fide of thofe planes 
will be 600 fquare inches ; which multiplied 

R by 

24 1 Anahfis of the Air. 

by the fum of all the veficles in the lungs, 
viz. ioo cubick inches, will produce 60000 
fquare inches; one third of which muft be 
dedu&ed, to make an allowance for the ab- 
fence of two fides in each little veficular 
cube, that there might be a free communi- 
cation among them for the air to pais to 
and fro ; fo there remain 40000 fquare 
inches for the fum of the furface of all the 

And the Brofichice containing 41 cubick 
inches, fuppofing them at a medium to be 
cylinders of ~i 6 of an inch diameter, their 
furface will be 1635 fquare inches, which 
added to the furface of the veficles, makes 
the fum of the furface of the whole lungs 
to be 41635 fquare inches, or 289 fquare 
feet, which is equal to 19 times the furface 
of a man's body, which at a medium is com- 
puted to be equal to 15 fquare feet. 

I have not had an opportunity to take in 
the fame manner the capacity and dimen- 
fions of human lungs; the bulk of which 
Dr. James Keill, in his Tentamina Medico- 
pbyfica, p. 80. found to be equal to 226 cu- 
bick inches. Whence he eftimated the fum 
of the furface of the veficles to be 21906 
fquare inches. But the bulk of human 


dnalyjis of the Air. 245 

lungs is much mote capacious than 226 cu- 
bick inches; for Tir.Jurin, by an accurate 
Experiment, found that he breathed out, at 
one large expiration, two hundred and twenty 
cubick inches of air; and I found it nearly 
the fame, when I repeated the like Experi- 
ment in another manner: So that there mull 
be a lar^e allowance made for the bulk of the 
remaining air, which could not be expired 
from the lungs; and alfo for the fubflance 
of the lungs. 

Suppofing then, that, according to T)r.Ju- 
riris eftimate, (in Mott *s Abridgment of the 
Philofophical TiranfaEl. Vol. I. p. 415.) we 
draw in at each common infpiration forty 
cubick inches of air, that will be 48000 cu- 
bick inches in an hour, at the rate of twenty 
infpirations in a minute. A confiderable part 
of the elafiicity of which air is, we fee by 
the foregoing Experiment, coriftantly de- 
ftroyed, and that chiefly among the veficlesj 
where it is charged with much vapour. 

But it is not eafy to determine how much 
is deftroyed. I attempted to find it out by 
the following Experiment, which I fhall here 
give an account of, tho' it did not fucceed 
fo well as I could have wifhed, for want cf 
much larger vefiels ; for if it was repeated 

R 2 with 

H4 Analyfis of the Air. 

with more capacious veffels, it would deter- 
mine the matter pretty accurately 5 becaufe 
by this artifice frefli air is drawn into the 
lungs at every infpiration, as well as in the 
free open air. 

Experiment CX. 
I made ufe of the fyphon (Fig. 39.) take^ 
ing away the bladders, and diaphragms i i 
n no: I fixed, by means of a bladder, one 
end cf a ftiort leaden fyphon to the lateral 
folTet i i : Then I fattened the large fyphon 
in a veffel, and filled it with water, till it 
rofe within two inches of a, and covered 
the other open end of the fhort fyphon, 
which was deprefTed for that purpofe. Over 
this orifice I placed a large inverted chymi- 
cal receiver full of water ; and over the other 
leg s of the great fyphon, I whelmed an- 
other large empty receiver, whofe capacity 
was equal to 1224. cubicle inches; the 
mouth of the receiver being immerfed in 
the water, and gradually let down lower 
and lower by an afliftant, as the water 
afcended in it. Then flopping my noftrils, 
I drew in breath at a, thro' the fyphon from 
the empty receiver : And when that breath 
was expired, the valve b i flopping its return 


Analyjis of the Jir. 245 

down thro* the fyphon, it was forced thro* 
the valve r, and thence through the fmall 
leaden fyphon into the inverted receiver full 
of water, which water defcended as the 
breath afcended. In this manner I drew all 
the air, except five or fix cubick inches, out 
of the empty receiver at 0, the water at the 
fame time afcending into it, and filling it ; 
by which means all the air in the empty 
receiver, as alfo all the air in the fyphon 
s b was infpired into my lungs, and breathed 
out through the valve r into the receiver, 
which was at firft full of water. I marked 
the boundary of air and water, and then 
immerfed the whole receiver, which had 
the breath in it, under water, and there gra- 
dually poured the contained breath up into 
the other full receiver, which flood inverted 
over S' y whereby I could readily find whe- 
ther the air had loft any of its elafticity : 
And for greater furety, I alfo meafured the 
bulk of breath, by filling the receiver with a 
known quantity of water up to the above- 
mentioned mark; making alfo due allow- 
ance for a bulk of air, equal to the capacity 
of the large fyphon s b } which was at laffc 
fucked full of water. 

* R 7 The 

a 46 Jnalyjis of the Air. 

The event was, that there were 18 cubick 
inches of air wanting; but as thefe receivers 
were much too fmall to make the Experi- 
ment with accuracy ; that fome allowance 
may be made for errors, I will fet the lofs 
of elaftick air at nine cubick inches, which 
is but TT6 P arc °f the whole air refpired, 
which will amount to 353 cubick inches in 
one hour, or 100 grains, at the rate of 84000 
cubick inches infpired in an hour, or five 
ounces 210 grains, in 24 hours. 

By pouring the like quantity of air to and 
fro under water, I found that little or none 
of it was loft; fo it was not abforbed by the 
water : To make this trial accurately, the 
air muft be detained fome time under water, 
to bring it firft to the fame temperature with 
the water. Care alfo muft be taken in make- 
}ng this Experiment, that the lungs be in the 
fame degree of contraction at the laft breath- 
ing, as at the firft ; elfe a confiderable error 
may arife from thence. 

But tho' this be not an exact eftimate, yet 
it is evident from the foregoing Experiments 
on refpiration, that fome of the elafticity of 
the air which is infpired is deftroyed; and 
that chiefly among the veficles, where it is 
moil loaded with vapours ; whence probably 


Analyfis of the Air. 247 

fome of it, together with the acid fpirits, 
with which the air abounds, are conveyed 
to the blood, which we fee is by an admi- 
rable contrivance there fpread into a vafl 
expanfe, commenfurate to a very large fur- 
face of air, from which it is parted by very 
thin partitions ; fo very thin, as thereby pro- 
bably to admit the blood and air-particles 
(which are there continually changing from 
an elaftickto a ftrongly attracting ftate) with- 
in the reach of each other's attraction, where- 
by a continued fucceffion of frefh air may be 
abforbed by the blood. 

And in the Analyfis of the blood, either 
by fire or fermentation in Exper. 49. and 80, 
we find good plenty of particles ready to re- 
fume the elaftick quality of air : But whe- 
ther any of thefe air -particles enter the 
blood by the lungs, is not eafy to deter- 
mine ; becaufe there is certainly great ftore 
of air in the food of animals, whether it be 
vegetable or animal food. Yet, when we 
confider how much air continually lofes its 
elafticity in the lungs, which feem purpofely 
framed into innumerable minute meanders, 
that they may thereby the better feize and 
bind that volatile Hermes : It makes it very 
probable, that thofe particles which are now 
R 4 changed 

M 8 Analjfis of the Air. 

changed from an elaftick, repulfive, to a 
ftrongly attracting ftate, may eafily be at- 
tracted thro 1 the thin partition of the veficles, 
by the fulphureous particles which abound in 
the blood. 

And nature feems to make ufe of the like 
artifices in vegetables, where we find that 
air is freely drawn in ; not only with the 
principal fund of nourishment at the root, 
but alfo thro* feveral parts of the body of 
the vegetable above ground ; which air was 
ktn to afcend in an elaftick ftate mod: freely 
and vifibly through the larger trachece of the 
Vine; and is thence doublefs carried with 
the fap into minuter veflels, where being in- 
timately united with the fulphureous, faline, 
and other particles, it forms the nutritive 
duftile matter, out of which all the parts of 
vegetables do grow. 

Experiment CXI. 

It is plain from thefe effects of the fumes 
of burning Brimfio?ie, lighted Candle, and 
the breath of Animals, on the elafticity of 
the air, that its elafticity in the veficles of 
the lungs muft be continually decreafing, by 
reafon of the vapours it is there loaded w T ith ; 
(6 that thole veficles would in a little time 


Jnalyfis of the Ak. 249 

fubfide and fall flat, if they were not fre- 
quently replenished with frefh elaftick air at 
every infpiration, thro* which the inferior 
heated vapour and air afcends, and leaves 
room for the frefh air to defcend into the 
veficles, where the heat of the lungs makes it 
expand about £ part ; which degree of ex- 
panfion of a temperate air, I found by in- 
verting a fmall glafs bubble in water, a little 
warmer than a thermometer is, by having its 
ball held fome time in the mouth, which 
may reafonably be taken for the degree of 
warmth in the cavity of the lungs. When 
the bubble was cool, the quantity of water 
imbibed by it was equal to \ of the cavity of 
the whole bubble. 

But when, inftead of thefe frequent recruits 
of frefh air, there is infpired an air, fur- 
charged with acid fumes and vapours, which 
not only by their acidity contract the exqui- 
fitely fenfible veficles, but alfo by their grofT- 
nefs much retard the free ingrefs of the air 
into the veficles, many of which are exceed- 
ing fmall, fo as not to be vifible without a 
microfcope - y which fumes are alfo continu- 
ally rebating the elafticity of that air; then 
the air in the veficles will, by Exper. 107, 
and 108, lofe its elafticity very faftj and 


2 jo Analyfn of the Air. 
confequently the veficles will fall flat, not- 
withftanding the endeavours of the extend- 
ing Thorax to dilate them as ufual j whereby 
the motion of the blood thro' the lungs being 
flopped, inftant death enfues. 

Which Hidden and fatal effect of thefe 
noxious vapours, has hitherto been fuppofed 
to be wholly owing to the lofs and wafte of 
the vivifying fpirit of air ; but may not 
unreafonably be alfo attributed to the lofs 
of a considerable part of the air's elafticity, 
and the groflhefs and denlity of the vapours, 
which the air is charged with 5 for mutually 
atta&ing particles, when floating in fo thin a 
medium as the air, will readily coalefce into 
grofler combinations : which effect of thefe 
vapours having not been duly obferved be- 
fore, it was concluded, that they did not 
affect the air's elafticity ; and that confe- 
quently the lungs muft needs be as much 
dilated in infpiration by this, as by a clear 

But that the lungs will not rife and dilate 
as ufual, when they draw in fuch noxious 
air, which decreafes faff in its elafticity, I 
was aflured by the Experiment I made on 
myfelf, in Exper. 108. for when towards the 
latter end of the minute, the fuffbeating qua- 

AnaJyJiS of the AW. 251 

lity of the air in the bladder was greateft, it 
was with much difficulty that I could dilate 
my lungs a very little. 

From this property in the vapours arife- 
ing from animal bodies, to rebate and de- 
ftroy part of the elafticity of the air, a pro- 
bable account may be given of what be- 
comes of a redundant quantity of air, which 
may at any time have gotten into the cavity 
of the Thorax, either by a wound, or by 
fome defed: in the fubftance of the lungs, 
or by very violent exercife. Which, if it 
was to continue always in that expanded 
ftate, would very much incommode refpi- 
ration, by hindering the dilatation of the 
lungs in infpiration. But if the vapours, 
which do continually arife in the cavity of 
the Thorax, deftroy fome part of the elafti- 
city of the air, then there will be room for 
the lungs to heave : And probably, it is in 
the fame manner that the winds are reforb- 
ed, which, in their elaftick ftate, fly from 
one part of the body or limbs to another, 
caufing by their diftention of the veflels much 


1 5 * jlnalyjis of the AW. 

Experiment CXII. 

I have by the following Experiment found, 
that the air will pafs here and there thro* the 
fubftance of the lungs, with a very fmall 
force, 'viz. 

I cut afunder the bodies of feveral young 
and fmall animals juft below the Diaphragm, 
and then taking care not to cut any veffel 
belonging to the lungs, I laid the Thorax 
open, by taking away the Diaphragm, and 
fo much of the ribs, as was needful to ex- 
pofe the lungs to full view, when blown up. 
And having cut off the head, I fattened the 
wind-pipe to a very fhort inverted leg of a 
glafs fyphon; and then placed the inverted 
lungs and fyphon in a large and deep glafs 
veffel x full of water, (Fig. 32.) under the 
air-pump receiver p p; and paffing the longer 
leg of the fyphon through the top of the 
receiver, where it was cemented faft at z, as 
I drew the air out of the receiver, the lungs 
dilated, having a free communication with 
the outward air, by means of the glafs fy- 
phon ; forne of which air would here and 
there pafs in a few places thro* the fubftance 
of the lungs, and rife in fmall ftreams thro' 
the water, when the receiver was exhaufted 


Analyfis of the Air. 1 5 5 
no more than to make the Mercury in the 
<*age fife lefs than two inches. When I ex- 
haufted the receiver, fo as to raife the Mer- 
cury feven or eight inches, though it made 
the air rufh with much more violence thro* 
thofe fmall apertures in the furface of the 
lungs, yet I did not perceive that the num- 
ber of thofe apertures was increafed, or at 
leaft very little. An argument that tj^ofe 
apertures were not forcibly made by exhauit- 
ing the receiver lefs than two inches, but 
were originally in the live animal. And 
that the lungs of living animals are fome- 
times raifed with the like force, efpecially in 
violent exercife^ I found by the following 
Experiment; viz* 

Experiment CXIII. 
I tied down a live Dog on his back, near 
the edge of a table, and then made a fmall 
hole through the intercoftal mufcles into his 
Thorax, near the Diaphragm. I cemented 
faft into this hole the incurvated end of a 
glafs tube, whofe orifice was covered with a 
litde cap full of holes, that the dilatation 
of the lungs might not at once flop the ori- 
fice of the tube. A fmall phial full of fpirit 
of Wine was tied to the bottom of the per- 

254 Analyjis of the Air. 

pendicular tube, by which means the tube 
and vial could eafily yield to the motion of 
the Dog's body, without danger of breaking 
the tube, which was 36 inches long. The 
event was, that in ordinary infpirations, the 
fpirit rofe about fix inches in the tube; but 
in great and laborious infpirations, it would 
rife 24 and 30 inches, viz. when I flopped 
the Dog's nofirils and mouth, fo that he 
could not breathe : This Experiment fhews 
the force with which the lungs are raifed 
by the dilatation of the Thorax, either in 
ordinary or extraordinary and laborious in- 
fpirations. When I blew air with fome force 
into the Thorax, the Dog was juft ready to 

By means of another {hort tube, which 
had a communication with that which was 
fixed to the Thorax, near its infertion into 
the Thorax, I could draw the air out of the 
Thorax, the height of the Mercury, inftead 
of fpirit in the tube, (hewing to what degree 
the Thorax was exhaufled of air : The Mer- 
cury was hereby raifed nine inches, which 
would gradually fubfide as the air got into 
the Thorax thro' the lungs. 

I then laid bare the wind-pipe, and having 
cut it off a little below the Larynx, I affixed 


Analyjis of the Air. 255 

to it a bladder full of air, and then conti- 
nued fucking air out of the 'Thorax, with a 
force fufficient to keep the lungs pretty much 
dilated. As the Mercury fubfided in the 
gage, I repeated the fudtion for a quarter of 
an hour, till a good part of the air in the 
bladder was either drawn thro* the fubftance 
of the lungs into the Thorax, or had loft its 
elafticity. When I prefTed the bladder, the 
Mercury fubfided the fafter ; the Dog was all 
the while alive, and would probably have 
lived much longer, if the Experiment had 
been continued 3 as is likely from the follow- 
ing Experiment, viz. 

Experiment CXIV. 

I tied a middle-fized Dog down alive on 
a table, and having laid bare his wind-pipe, 
I cut it afunder juft below the Larynx, and 
fixed faft to it the fmall end of a common 
foffet ; the other end of the foffet had a large 
bladder tied to it, which contained 162 cu- 
bick inches ; and to the other end of the 
bladder was tied the great end of another 
foffet, whofe orifice was covered wich a valve, 
which opened inward, fo as to admit any air 
that was blown into the bladder, but none 
could return that way ; yet for further fecu- 


156 Analyjis of the Air. 

rity, that paffage was alfo flopped with a 


As foon as the firft foffet was tied faft to 
the wind-pipe, the bladder was blown full of 
air thro' the other foffet -, when the Dog had 
breathed the air in the bladder to and fro 
for a minute or two, he then breathed very 
faft, and (hewed great uneafinefs, as being 
almoft fuffocated. 

Then with my hand I preffed the bladder 
hard, fo as to drive the air into his lungs with 
fome force -, and thereby make his Abdomen 
rife by the preffure of the Diaphragm, as in 
natural breathings : Then taking alternately 
my hand off the bladder, the lungs with the 
Abdomen fubfided ; I continued in this man- 
ner to make the Dog breathe for an hour ; 
during which time I was obliged to blow 
f;efh air into the bladder every five minutes, 
three parts in four of that air being either 
abforbed by the vapours of the lungs, or 
efcaping thro' the ligatures, upon my pref- 
fing hard on the bladder. 

During this hour, the Dog was frequently 
near expiring, whenever I preffed the air 
but weakly into his lungs 5 as I found by 
his pulfe, which was very plain to be felt 
in the great crural artery near the groin, 


Analyfis of the Air. 257 

which place an affiftant held his finger on 
moft pare of the time; but the languid pulfe 
was quickly accelerated, fo as to beat fart ; 
foon after I dilated the lungs much, by pref- 
ling hard upon the bladder, efpecially when 
the motion of the lungs was promoted by 
preffing alternately the Abdomen and the blad- 
der, whereby both the contraction and dila- 
tation of the lungs was increafed. 

And I could by this means roufe the lan- 
guid pulfe whenever I pleafed, not only at 
the end of every five minutes, when more air 
was blown into the bladder from a man's 
lungs, but alfo towards the end of the five 
minutes, when the air was fulleft of fumes. 

At the end of the hour, I intended to try 
whether I could by the fame means have kept 
the Dog alive fome time longer, when the 
bladder was filled with the fumes of burning 
Brimftone : But being obliged to ceafe for a 
little time from prefiing the air into his lungs, 
while matters were preparing for this addi- 
tional Experiment, in the mean time the Dog 
died, which might otherwife have lived lon- 
ger, if I had continued to force the air into 
his lungs. 

Now, though this Experiment was fo fre- 
quently diflurbed, by being obliged to blow 

S more 

258 dnalyjis of the Air. 

more air into the bladder twelve times da- 
ring the hour; yet fince he was almoft fuf- 
focated in lefs than two minutes, by breath- 
ing of himfelf to and fro the firft air in the 
bladder, he would, by Experiment 106. on 
Candles, have died in lefs than two minutes, 
when one fourth of the old air remained in 
the bladder, immediately to taint the new 
admitted air from a man's lungs -> to that his 
continuing to live through the whole hour, 
muft be owing to the forcible dilatation of 
the lungs, by compre fling the bladder, and 
not to the vivifying fpirit of air. For with- 
out that forcible dilatation, he had, after the 
firft five or ten minutes, been certainly dead 
in lefs than a minute, when his pulfe was fo 
very low and weak, which I did not find to be 
revived barely by blowing three parts in four 
of new air from the lungs of a man into the 
bladder : But it was conftantly roufed and 
quickned, whenever I increafed the dilata- 
tions of the lung?, by comprefling the bladder 
more vigoroufly ; and that whether it was at 
the beginning or end of each five minutes, 
yet it was more eafily quickned, when the 
bladder was at any time newly filled, than 
when it was near empty. 


dnalyfis of the Air. 259 

From thefe violent and fatal cffeds of very 
noxious vapours on the refpiratibn and life 
of animals, we may fee how the refpiration 
is proportionately incommoded, when the air 
is loaded with leiTer degrees of vapours, which 
vapours do, in fome meafure, clog and lower 
the air's elafticity $ which it befl regains by 
having thefe vapours difpelled by the venti- 
lating motion of the free open air* which 
is rendered wholefome by the agitation of 
winds : Thus, what we call a clofe warm 
air, fuch as has been long confined in a room, 
without having the vapours in it carried off 
by communicating with the open air, is apt 
to give us more or lefs uneafinefs, in pro- 
portion to the quantity of vapours which 
are floating in it. For which reafon the 
German ftoves* which heat the air in a room 
without a free admittance of fre(h air to 
carry off* the vapours that are raifed, as alfo 
the modern invention to convey heated air 
into rooms through hot flues, feem not fo 
well contrived, to favour a free refpiration, 
as our common method of fires in open 
chimneys, which fires are continually car- 
rying a large ftream of heated air out of the 
rooms up the chimney, which ftream muft 
neceflarily be fupplied with equal quantities 
S 2 of 

i6o Analyfis of the Air. 

of frefli air, through the doors and windows, 

or the cranies of them. 

And thus many of thofe who have weak 
lungs, but can breathe well enough in the 
frefh country air, are greatly incommoded 
in their breathing, when they come into 
large cities, where the air is full of fuligi- 
nous vapours, ariiing from innumerable coal 
fires, and flenches from filthy lay-ftalls and 
fewers : And even the moft robuft and heal- 
thy, in changing from a city to a country 
air, find an exhilarating pleafure, arifing from 
a more free and kindly infpiration, whereby 
the lungs being lefs loaded with condenfing 
air and vapours, and thereby the veficles 
more dilated, with a clearer and more e|a- 
ftick air, a freer courfe is thereby given to 
the blood, and probably a purer air mixed 
with it 5 and this is one reaibn why in the 
country a ferene dry conftitution of the air 
is more exhilarating than a moifl thick air. 

And for the fame reafon, it is no wonder, 
that peftijential and other noxious epidemi- 
cal infections are conveyed by the breath to 
the blood (when we confider what a great 
quantity of the airy vehicle lofes its elafti- 
city among the veficles, whereby the infe- 
ctious Miafma is lodged in the lungs). 


Jnalyjis of the Air. 2 6 1 
When I reflect on the great quantities of 
elaftick air, which are deftroyed by fulphu- 
reous fumes ; it feems to me not improba- 
ble, that when an animal is killed by light- 
ning without any vifible wound, or imme- 
diate ftroke, that it may be done by the air's 
elafticity, being inftandy deftroyed by the 
fulphureous lightning near the animal; 
whereby the lungs will fall flat, and caufe 
fudden death ; which is further confirmed 
by the flatnefs of the lungs of animals thus 
killed by lightning, their veficles being found 
upon diflection to be fallen flat, and to have 
no air in them : The burfting alio of glafs- 
windows outwards, fecms to be from the 
fame effect of lightning on the air's elafti- 

It is likewife by deftroying the air's elafti- 
city in fermented liquors, that lightning ren- 
ders them fiat and vapid: For fince fulphu- 
reous fteams held near or under veflels will 
check redundant fermentation, as well as the 
putting of fulphureous mixtures into the li- 
quor, it is plain, thofe fteams can eaiily pe- 
netrate the wood of the containing vefTels. 
No wonder then, that the more fubtile 
lightnings fhould have the like effects. I 
S 3 know 


i6x JnaJyJis of the Air. 

know not whether the common practice of 
laying a bar of iron on a veffel, be a good 
prefervative againft the ill effects of lightning 
on liquors. I fhould think, that the cover- 
ing a veffel with a large cloth dipped in a 
ftrong brine, would be a better prefervative; 
for falts are known to be ftrong attraclers of 

The certain death which comes on the 
explofion of Mines, feems to be effected in 
the fame manner : For though at firft there 
is a great expanfion of the air, which muff 
dilate the lungs, yet that air is no fooner 
filled with fuliginous vapours, but a good 
deal of its elafticity is immediately deftroyed: 
As in the cafe of burning Matches in Expe- 
riment 103. the heat of the flame at firft 
expanded the air ; but notwithstanding the 
flame continued burning, it immediately con- 
tracted, and loft much of its elafticity, as 
foon as fome quantity of fulphureous fleams 
afcended in it. 

Which fteams have doubtlefs the fame 
effect on the air, in the lungs of animals held 
over them, as in the Grotto di cani y or when 
a clofe room is filled with them, where they 

certainly fuffocate. 


Analjjts of the Air. 265 

It is found by Experiments 103, 106, and 
107, that an air greatly charged with vapours 
lofes much of its elafticity, which is the rea- 
fon why fubterraneous damps fuffocate ani- 
mals, and extinguish the flame of candles- 
And by Experiment 106, we fee that the 
fooner a Candle goes out, the fafter the air 
lofes its elafticity. 

Experiment CXV. 

This put me upon attempting to find fome 
means to qualify and rebate the deadly noxi- 
ous quality of thefe vapours : And in order 
to it, I put thro' the hole, in the top of the 
air-pump receiver, (Fig. 32.) which contained 
two quarts, one leg of an iron fyphon made 
of a gun-barrel, which reached near to the 
bottom of the receiver : It was cemented fail 
at z. I tied three folds of woollen cloth over 
the orifice of the fyphon, which was in the 
receiver. The candle went out in lefs than 
two minutes, tho* I continued pumping all 
the while, and the air pafled fo freely thro' 
the folds of cloth into the receiver, that the 
Mercury in the gage did not rife above an 

When I put the other end of the fyphon 
into a hot iron pot, with burning Brimjione 

S 4 in 

1 6 f Analyfis of the Ah. 

in it ; upon pumping, the candle went out 
in 15 feconds of a minute; but when I took 
away the three folds of cloth, and drew the 
fulphureous fleams thro' the open fyphon, 
the light of the candle was inftantly extin- 
guifhed ; whence we fee the 3 folds of cloth 
preferved the candle alight 15". And where 
the deadly quality of vapours in mines is not 
fo ftrong as thefe fulphureous ones were, the 
drawing the breath through many folds of 
woollen cloth may be a means to prefervelife 
a little longer, in proportion to the more or 
lefs noxious quality of the damps. 

When, infteadof the three folds of cloth, I 
immerfed the end of the fyphon three inches 
deep in water in the veffel x y (Fig. 32.) tho' 
upon pumping the fulphureous fumes did 
afcend vifibly through the water, yet the 
candle continued burning half a minute, i. e. 
double the time that it did when fumes pafTed 
thro' folds of woollen cloth. 

Experiment CX VI. 

I bored a hole in the fide of a large wooden 
foflet ab, (Fig. 30.) and glewed into it the 
great end of another fofiet i /, covering the 
1 Gee with a bladder valve r: Then I fit- 
ted a valve b i 7 to the orifice of the iron 


Analyjis of the Air. 165 

fyphon S S y fixing the end of the fyphon faft 
at b into the foflet a b : Then by means of 
narrow hoops I placed four Diaphragms of 
flannel at half an inch diftance from each 
other, into the broad rim of a fieve, which 
was about feven inches diameter. The fieve 
was fixed to, and had a free communication 
with, both orifices of the fyphon, by means 
of two large bladders i i n ?i 0. 

Linen would probably be more proper to 
make thefe Diaphragms of than flannel, be- 
caufe oil or greafe is ufed in the making of 
flannel : And as I have heard, it is whitened 
by the fumes of burning Brimjlone; which I 
was not aware of, when I made uie of flannel 
in thefe Experiments. 

The inftrument being thus prepared, 
pinching my noftrils clofe, when I drew in 
breath with my mouth at a, the valve i b 
being thereby lifted up, the air paflfed freely 
through the fyphon from the bladders, 
which then fubfided, and fhrunk confider- 
ably: But when I breathed air out of my 
lungs, then the valve i b clofing the orifice 
of the fyphon, the air pafied thro' the valve 
r into the bladders, and thereby ^- dilated 
them •> by which artifice the air which I ex- 
pired muft necefiarily pafs thro' all the Dia- 


266 Analyfis of the Air. 

pbragms, before it could be infpired into my 
lungs again. The whole capacity of the 
bladders and fyphon was 4 or 5 quarts. 

Common fea-falt, and Sal Tartar, being 
ftrong imbibers of fulphureous fteams, 1 dip- 
ped the four Diaphragms in ftrong folutions 
of thofe falts, as alfo in white- wine vinegar, 
which is looked upon as a good anti-pefti- 
lential : Taking care after each of thefe Ex- 
periments to cleanfe the fyphon and bladder 
well from the foul air, by filling them with 

I could breathe to and fro the air inclofed 
in this inftrument for a minute and half, 
when there were no Diaphragms in it ; when 
the four Diaphragms were dipped in vinegar, 
three minutes ; when dipped in a ftrong folu- 
tion of fea-falt, three minutes and an half. 
In a Lixivium of Sal Tartar, three minutes; 
when the Diaphragms were dipped in the 
like Lixivium, and then well dried, five mi- 
nutes ; and once 8 -j- \ minutes, with very 
highly calcined Sal Tartar -, but whether 
this was owing to the Tartar s being greatly 
calcined, whereby it might more ftrongly 
attradl fulphureous grofs vapours, or whe- 
ther it was owing to the bladder and fyphon's 
being intirely dry, or whether it was occa- 


Analyjis of the Air. 2^7 

iioned by fome unheeded paiTage for the air 
thro' the ligatures, I am uncertain ; neither 
did I care to afcertam the matter by repeated 
Experiments, fearing I might thereby fome 
way injure my lungs, by frequently breathing 
in fuch grofs vapours. 

Hence Sal Tartar fhould be the bell: pre- 
fervative againft noxious vapours, as being a 
very ftrong imbiber of fulphureous, acid and 
watry vapours, as is fea-falt alfo : For having 
carefully weighed the four Diaphragms be- 
fore I fixed them in the inftrument, I found 
that they had increafed in weight 30 grains 
in five minutes 5 and it was the fame in two 
different trials; fo they increafed in weight 
at the rate of 1 9 ounces in 24 hours. From 
which deducting £ part of the quantity of 
moifture, which I found thofe Diaphragms 
attracted in 5 minutes in the open air ; there 
remain 15 -J- -| ounces, for the weight of 
the moifture from the breath in 24 hours : 
But this is probably too great an allowance, 
confidering that the Diaphragms might at- 
tract more than £ part from the moifture of 
the bladders and of the fyphon. See Exper. 6. 
Vol. II. Appen. p. 323. 

I have found, that when the Diaphragms 
had fome fmall degree of dampnefs, they 


268 Analyfis of the Air. 

increafed in weight fix grains in three minutes -, 
but they made no increafe in weight in the 
fame time, when in the open air : which fix 
grains in three minutes is at the rate of about 
6 + |ounces in 24 hours 3 and this is nearly 
the fame proportion of moifture that I ob- 
tained by breathing into a large receiver full 
of fpunges. But the fix grains imbibed by 
the four Diaphragms in three minutes, was 
not near all the vapours which were in that 
bulk of inclofed air ; for at the end of the 
three minutes, the often refpired air was fo 
loaded with vapours, which in that floating 
ftate were eafily, by their mutual attraction, 
formed into combinations of particles, too 
grofs to enter the minute veficles of the 
lungs, and was therefore unfit for refpira- 
tion ; fo that it is not eafy to determine what 
proportion is carried off by refpiration, efpe- 
cially confidering that fome of the infpired 
air, which has loft its elafticity in the lungs, 
is mingled with it. But fuppofing 6 + x 
ounces to be the quantity of moifture car- 
ried off by refpiration in twenty-four hours, 
then the furface of the lungs being found, 
as above, 41635 fquare inches, only y^T P art 
of an inch depth will be evaporated off 
their inward furface in that time, which 


AnaJyJis of the Air. 269 

is but JL part of the depth of what is per- 
fpired off the furface of a man's body in that 

If then life can by this means be fupported 
for five minutes with four Diaphragms and 
a gallon of air, then doubtlefs, with double 
that quantity of air and eight Diaphragms, 
we might well expect to live at leaft ten mi- 
nutes. It was a confiderable difadvantage, 
that I was obliged to make ufe of bladders, 
which had been often wetted and dried, fo 
that the unfavoury fumes from them muft 
needs have contributed much to the unfitting 
the included air for refpiration : Yet there 
is a neceffity for making ufe of either blad- 
der or leather in thefe cafes ; for we cannot 
breathe to and fro the air of a veffel, whofe 
fides will not dilate and contract in confor- 
mity with the expirations and infpirations, 
unlefs the veffel be very large, and too big 
to be conveniently portable. 

Having flopped up the wide fucking ori- 
fice of a large pair of kitchen bellows, they 
being firfl dilated, I could breathe to and fro 
at their nofe, the air contained in them for 
more than three minutes, without much in- 
convenience, they heaving and falling very 
eafily by the action of refpiration. Some 


17 o Analyjis of the Air. 

fuch-like inftrument might be of ufe in any 
cafe, where a room was filled with fuffbca- 
ting vapours, where it might be neceffary to 
enter for a few minutes, in order to remove 
the caufe of them, or to fetch any perfon or 
thing out; as in the cafe when houfes are 
firft beginning to fire, in the Chymifts ela- 
boratories ; and in many other cafes, where 
places were filled with noxious deadly va- 
pours, as in the cafe of ftink-pots thrown 
into (hips, in mines, &c. And might it not 
alfo be ferviceable to Divers ? 

But in every apparatus of this kind great 
care muft always be taken, that the infpira- 
tion be as free as poffible, by making large 
paffages and valves to play moll: eafily. For 
tho' a man by a peculiar action of his mouth 
and tongue may fuck Mercury 22 inches, 
and fome men 27 or 28 high ; yet I have 
found by experience, that by the bare infpi- 
ring aftion of the Diaphragm, and dilating 
Thorax y I could fcarcely raife the Mercury 
two inches. At which time the Diaphragm 
muft a£t with a force equal to the weight of 
a Cylinder of Mercury, whofe bafe is com- 
menfurate to the area of the Diaphragm, and 
its height two inches, whereby the Dia- 
phragm muft at that time fuftain a weight 


AnaJyJis of the Air. 271 

equal to many pounds. Neither are its 
counter-aCting mufcles, thofe of the Abdomen* 
able to exert a greater force. 

For notyvithftanding a man, by ftrongly 
compreffing a quantity of air included in his 
mouth, may raife a column of Mercury in 
an inverted fyphon, to five or feven inches 
height, yet he cannot, with his utmoft {train- 
ings, raife it above two inches, by the con- 
tracting force of the mufcles of the Abdomen; 
whence we fee that our loudeft vociferations 
are made with a force of air no greater than 
this. So that any fmall impediment in breathe- 
ing will haften the fuffocation, which con- 
fifts chiefly in the falling flat of the lungs, 
occafioned by the groflhefs of the particles 
of a thick noxious air, they being in that 
floating ftate mod eafily att rafted by each 
other : As we find in the foregoing Experi- 
ments that fulphur and the elaftick repelling 
particles of air do : And confequently unela- 
ftick, fulphureous, faline, and other floating 
particles will moft eafily coalefce ; whereby 
they are rendered too grofs to enter the mi- 
nute veficles; which are alfo much con- 
tracted, as well by the lofs of the elafticity 
of the contained air, as by the contraction 
Occafioned by the ftimulating, acid, fulphu- 

27 * Analyfis of the Air. 

reous vapours. And it is not improbable, 
that one great defign of nature, in the ftru- 
cture of this important and wonderful vifcus, 
was to frame its veficles fo very minute, 
thereby effectually to hinder the ingrefs of 
grofs feculent particles, which might be inju- 
rious to the animal oeconomy. 

This quality offalts ftrongly to attract ful- 
phurecus, acid, and other noxious particles, 
might make them very beneficial to man- 
kind in many other refpects. Thus in feve- 
ral unwholefome trades, as the fmelters of 
metals, the cerufs-makers, the plumbers, GV. 
it might not unlikely be of good fervice to 
them, in preferving them, in fome meafure 
at leaft, from the noxious fumes of the ma- 
terials they deal in, which by many of the 
foregoing Experiments we are allured mufl 
needs coalefce with the elaftick air in the 
lungs, and be lodged there ; to prevent which 
inconvenience the workmen might, while 
they are at work, make ufe of pretty broad 
mufflers, filled with two, four, or more 
Diaphragms of flannel or cloth dipped in a 
folution of Sal Tartar or Pot-aft, or Sea-Salt, 
and then dried. 

The like mufflers might alfo be of fervice 
in many cafes where perfons may have urgent 


Analyjis of the Ak. 275 

occafion to go for a fhort time into an in- 
fectious air : Which mufflers might, by an 
eafy contrivance, be fo made as to draw in 
breath thro' the Diaphragms, and to breache 
it out by another vent. 

In thefe and the like cafes this kind of 
mufflers may be very ferviceable 5 but in the 
cafe of the damps of mines they are by no 
means to be depended on, becaufe they are 
not a fufficient fcreen from fo very noxious 

Experiment CXVII. 

We have from the following Experiment 
a good hint, to make thefe Salts of fervice to 
us in fome other refpedls, GV. 

I fet a lighted Candle under a large receiver 
(Fig. 35) which contained about four gal- 
lons 5 it continued burning for 3 + i. mi- 
nutes, in which time it had abforbed about 
a quart of air. I then filled the receiver with 
frefh air, by pouring it full of water, and 
then emptying of it , when having wiped it 
dry, I lined all the infide with a piece of 
flannel dipped in a Lixivium of Sal c lartar y 
and then dried ; the flannel was extended 
with little hoops made of pliant twigs. The 
Qandle continued burning under the receiver 

T thus 

274 Analyfis of the Air. 

thus prepared 3 + \ minutes ; yet it abforbed 
but two thirds of the quantity of air which 
it abforbed when there was no flannel in the 

The reafon of which difference in the 
quantities of elaftick air abforbed, appears 
from Experiment 106, where leaft air was 
always abforbed in leaft receivers, which was 
the prefent cafe: For the flannel lining, be- 
iides the fpace it took up, could not be fo 
clofely adapted, but that there was left a full 
third of the capacity of the receiver, between 
the lining and the receiver : So that the Candle 
burnt in a bulk of air lefs by one third than 
the whole capacity of the receiver > for which 
reafon lefs air alfo was abforbed. 

And we may further obferve, that fince the 
Candle continued burning as long in a quan- 
tity of air, equal but to two thirds of the re- 
ceiver, as in the whole air of the receiver j 
this muft be owing to the Sal "Tartar in the 
flannel lining, which muft needs have abforbed 
one third of the fuliginous vapours, which 
arofe from the burning candle. Hence we may 
not unreafonably conclude, that the pernicious 
quality of noxious vapours in the air might, 
in many cafes, be much rebated and qualified 
fey the ftrcngly abforbing power of Salts. 


Analyfis of the Air. 275 

Whether Salts will have a good effect in 
all, or any of thefe cafes, experience will 
beft inform us. There is certainly fufficient 
ground, from many of the foregoing Expe- 
riments, to encourage us to make the trial, 
and they may at leaft be hints for further im- 

We fee that Candles and burning Brim- 
fione do in a much greater degree deftroy 
the elafticity of the air, than the breath of 
Animals ; becaufe their vapours are more 
plentiful, and abound more with acid ful- 
phureous particles, and are alfo lefs diluted 
with watry vapours, than the breath of Ani^ 
mals is: In which alfo there are fulphureous 
particles, tho' in leffer degrees; for the ani- 
ma-1 fluids, as well as folids, are ftored with 
them: And therefore the Candle and Matches 
ceafing to burn, foon after they are confined 
in a fmall quantity of air, feems not to be 
owing to their having rendred that air effete, 
by having confumed its vivify i?ig fpirit ; but 
mould rather be owing to the great quantity 
of acid fuliginous vapours, with which that 
air is charged, which deftroy a good deal of 
its elafticity, and very much clog and retard 
the elaftick motion of the remainder. 

T 2 And 

27 6 Anatyfis of the Air. 

And the effedt the half exhaufting of a 
receiver has upon the elafticrty of the remain- 
ing half of the air, feems to be the reafon 
why the flame of a Candle does not con- 
tinue burning, till it has filled the receiver 
it ftands in with fumes ; but goes out the 
quicker, the fooner the air is drawn out to 
that degree ; which feems therefore to be 
owing to this, that an air rarefied to double 
its fpace, will not expand fo briskly with the 
warmth of flame, as a more condenfed air 
will do r And confequently action and re- 
action being reciprocal, will not give fo brisk 
a motion to the flame, which fubfifts by a 
conftant fucceffion of frefli air, to fupply the 
place of the either abforbed, or much dilated 
air, which is continually flying off. And the 
quicker the fucceflion of this frefli air is, by 
blowing, the more vigoroufly does a fire 

If the continuance of the burning of the 
Candle be wholly owing to the vivifying 
Jpirit, then fuppofing in the cafe of a re- 
ceiver, capacious enough for a Candle to burn 
a minute in it, that half the vivifying fpirit 
be drawn out with half the air, in ten fecond3 
of time ; then the Candle fhould not go out 
at the end of thole ten feconds > but burn 


Analyjis of the An. 17 7 

twenty feconds more, which it does not ; 
therefore the burning of the candle is not 
wholly owing to the vivifying fpirit, but to 
certain degrees of the air's elafticity. When 
a wholly exhaufted receiver was by means of 
a burning-glafs firft filled with the fumes of 
brown paper with Nitre, and then filled 
with frefh air, the nitrous paper, upon ap- 
plying the burning-glafs, did freely detonize; 
and a Candle put into a like air, burnt for 2 8" 5 
which in a frefh air, in the fame receiver? 
burnt but 43" ; but when the fame receiver, 
with air in it, was filled full of fumes of 
detonized Nitre, and a Candle placed in that 
thick vapour, it went out inflantly ; for a 
Candle will not burn, nor the Nitre deto- 
nize in a very rare, nor a very thick air ; 
whence the reafon why the Nitre detonized, 
and the Candle burnt, when placed in the 
receiver, after frefh air was let in upon 
the fumes which were made in vacuo, was, 
that thofe fumes were much difperfed and 
condenfed on the fides of the glafs, upon 
the rufhing in of the frefh air; for the fumes 
were then much more rare and tranfparent, 
than before the air was let in. 

That a Fire which is fupplied with a hot 
air will not burn fo briskly as a Fire which 

T 3 is 

2/8 Jnalyfis of the Air. 

is fed by a cool air, is evident from hence ; 
that when the Sun fhines on a Fire, and 
thereby too much rarefies the ambient air, 
that Fire will not burn well ; nor will a 
final 1 Fire burn fo well near a large one, as 
at fome diftance from it. And e centra, it 
is a common obfervation, that in very cold 
frofty weather, Fires burn moft briskly ; the 
reafon of which feems to be this, that the 
elaftick expanfion of the cold condenfed air 
to a rarefied Hate, when it enters the Fire, is 
much brisker than that of an air already 
rarefied in a good meafure by heat, before it 
enters the Fire; and confequently a conti- 
nued fucceffion of cold air muft give a brisker 
motion to the Fire, than the like fucceflion 
of hot air: And fuch colder and more con- 
denfed air will alfo (as Sir Ifaac Newton ob- 
ferves qu. 11) by its greater w r eight check 
the afcent of the vapours and exhalations of 
the Fire, more than a warmer lighter air. 
So that between the action and re-action of 
the air and fulphur of the fuel, and of the 
colder and denfer circumambient air, which 
rarefies much upon entring the Fire, the heat 
of the Fire is greatly increafed. See Vol. II. 

/•3 2 9- 


Jnalyfis of the Air. 179 

This continual fupply of frefh air to the 
fuel, feems hence alfo very neceffary for keep- 
ing a Fire alive ; becaufe it is found, that a 
Brimfione Match will not take fire in a va- 
cuum, but only boil and fmoke ; nor will 
Nitre incorporated into Brown Paper then 
detonize, except here and there a fingle grain, 
that part only of the Paper turning black, on 
which the focus of the burning-glafs falls ; 
nor would they burn when a half-exhaufted 
receiver with fumes in it was filled with frefli 
air added to thofe fumes : In which cafe it 
is plain, that a good quantity of the fup- 
pofed vivifying fpirii of air muft enter 
the receiver with the frefli air, and confe- 
quently thofe fubftances fhould take fire, and 
bum for a fhort time at leaft, which yet they 
did not. 

And that the air's elafticity conduces much 
to the intenfe burning of Fires, feems evident 
from hence ; that Spirit of Nitre (which, by 
Experiment 75, has but little elaflick air in 
it) when poured upon live Coals, extinguishes 
inftead of invigorating them : But Spirit of 
Nitre, when by being mixt with Sar Tartar 
it is reduced to Nitre, will then flame, when 
thrown into the Fire, viz. becaufe Sal Tartar 
abounds with elaflick aereal particles, as ap- 

T 4 pears 

2 8 o Analyjis of the Ah. 

pears by Experiment 74, where 224 times 
its bulk of air arofe from a quantity of Sal 
Tartar. And for the fame reafon it is that 
common Nitre, when thrown into the Fire, 
flames, tho' its Spirit will not, viz. becaufe 
there is much elaftick air in it, as appears 
from Experiment 72, as well as from the 
great quantity of it, generated in the firing 
of Gun-powder. 

The reafon why Sal Tartar ', when thrown 
on live Coals, does not detonize and flame 
like Nitre, (notwithftanding, by Experiment 
74, plenty of elaftick particles did arife from 
it) is this, viz. becaufe by the fame Experi- 
ment, compared with Experiment 72, it is 
found, that a much more intenfe degree of 
heat was required to extricate the elaftick air 
from Sal Tartar, the more fix'd body, than 
from Nitre -, the great degree of Fire with 
which Sal Tartar is made, rendering the 
cohefion of its parts more firm : For it is 
well known that Fire, inftead of difuniting, 
does in many cafes infeparably unite the parts 
of bodies: And hence it is that Pidvis Ful- 
mi'rians, which is a mixture of Sal Tartar, 
Nitre and fulphur, gives a greater explofion 
than Gun-powder : Becaufe the particles of 
the Sal Tartar cohering more firmly in a 


Analyfis of the Air. 8 1 \ 

fix'd ftate than thofe of 'Nitre, they are there- 
fore thrown off with a greater repulfive force, 
by the united action and re-action of all thofe 
ingredients armed each with its acid Spirit. 

Experiment CXVIII. 

Which acid Spirits, confifting of a volatile 
acid Salt diluted in phlegm, do contribute 
much to the force of explofion; for when 
heated to a certain degree, they make a great 
explofion, like water heated to the fame de- 
gree, as I found by dropping a few drops of 
Spirit of Nitre, oil of Vitriol, water, and 
fpittle, on an Anvil; and then holding over 
thofe drops a piece of Iron, which had a 
white heat given it ; upon flriking down the 
hot Iron with a large Hammer, there was a 
very great explofion made by each of thofe 
liquors: But frothy fpittle, which had air in 
it, made a louder explofion than water; which 
fhews that the van: explofion of the Nitre and 
Sal Tartar, which are compofed of elaftick 
air-particles, included in an acid Spirit, is 
owing to their united force. 

We may therefore, from what has been 
faid, with good reafon conclude, that Fire is 
^hiefly invigorated by the action and re-aftion. 


2 8 1 Analyfis of the Air. 

of the acid fulphureous particles of the fuel, 
and the elaftick ones, which arife and enter 
the Fire, either from the fuel in which they 
abound, or from the circumambient air : For 
by Experiment 103, and many others, acid 
fulphureous particles act vigoroufly on air ; 
and fince action and re-action are reciprocal, 
fo muft air on fulphur ; and there is, we fee, 
plenty of both, as well in mineral as vege- 
table fuel, as alfo in animal fubftances, for 
which reafon they will burn. 

But when the acid fulphur, which we fee 
acts vigoroufly on air, is taken out of any 
fuel, the remaining Salt, water and earth, are 
not inflammable, but on the contrary, quench 
and retard fire; and as air cannot* produce 
fire without fulphur, fo neither can fulphur 
burn without air : Thus Charcoal heated to 
an intenfe degree for many hours in a clofe 
veflel, will not burn as in the open air; it 
will only be red-hot all the time, like a mafs 
of Gold, without wafting : But no fooner is 
it expofed to the free air, but the fulphur, 
by the violent action and re-action between 
that and the elaftick air, is foon feparated and 
carried off from the Salt and Earth, which 
are thereby reduced from a folid and hard, to 
a foft impalpable Calx. 


Analyfis of the Air. 285 

And when a Brimjlone Match, which was 
placed in an exhaufted receiver, was heated 
by the focus of a burning-glafs fo as to melt 
the Brimjlone, yet it did not kindle into fire, 
nor confume, notwithstanding the ftrength 
and vigour of the adtion and re-adtion that is 
obferved between light and fulphureous bo- 
dies. Which is affigned by the illuftrious Sir 
Ifaac Newton, as " one reafon why fulphu- 
" reous bodies take fire more readily, and 
" burn more vehemently than other bodies 
u do, Qu. 7." What his notion of fire and 
flame is, he gives us in Qu. 9. and 10. Qu^c?. 
" Is not Fire a body heated fo hot as to emit 
" light copioufly ? For what elfe is a red-hot 
" Iron than Fire ? And what elfe is a burn- 
<c ing Coal, than red-hot Wood?" Qu. 10. 
<c Is not Flame a vapour, fume or exhalation, 
" heated red-hot, that is, fo hot as to flame? 
< c For bodies do not flame without emitting 
" a copious ftfme, and this fufne burns in 

<c the flame. Some bodies heated bv 

motion or fermentation, if the heat grow 
intenfe, fume copioufly ; and if the heat be 
great enough, the fumes will fhine, and 
ic become flame : Metals in fufion do not 
" flame for want of a copious fume, except 
" fpelter, which fumes copioufly, and there- 

" by 



284 Analyfis of the Air. 

" by flames: All flaming bodies, as Oil, 
Tallow, Wax, Wood, foffil Coals, Pitch, 
Sulphur, by flaming wafte and vanifh into 
burning fmoak ; which fmoak, if the flame 
<c be put out, is very thick and vifible, and 
lc fometimes fmells ftrongly, but in flame 
u lofes its fmell by burning ; and according 
<c to the nature of the fmoak the flame is 
u of feveral colours, as that of fulphur, blue ; 
€C that of copper opened with fublimate, 
<c green; that of tallow, yellow; that of 
" camphire, white ; fmoak pafling through 
cc flame cannot but grow red-hot ; and red- 
cc hot fmoak can have no other appearance 
cc than that of flame." 

But Mr. Lemery the younger fays, " That 
" the matter of light produces fulphur, be- 
cc ing mixt with compofitions of fait, earth, 
" and water, and that all inflammable mat- 
t€ ters are fuch only in virtue of the parti- 
<{ cles of fire which they contain. For in 
" the Analyfis, fuch inflammable bodies pro- 
" duce fait, earth, water, and a certain fubtle 
" matter, which pafles through the clofeft 
" veflels ; fo that what pains foever the artift 
<c ufes, not to lofe any thing, he ftill finds a 
u confiderable diminution of weight. 




Analyfts of the Ait. 285 

" Now thefe principles of fait, earth and 
" water, are inactive bodies, and of no ufe, 
u in the compofition of inflammable bodies, 
" but to detain and arreft the particles of fire, 
" which are the real and only matter of 
u flame. 

" It appears therefore to be the matter of 
<c flame that the artift lofes in decompound- 
<c ing inflammable bodies, Mem. de I'Acad. 
cc anno 1713." 

But by many of the preceding Experiments 
it is evident, that the matter loft in the Ana- 
lyfis of thefe bodies was elaftick air, a very 
adtive principle in fire, but not an elemental 
fire, as he fuppofes. 

" Mr. Geoffrey compounded fulphur of 
" acid Salt, Bitumen, a little Earth, and Oil 
" of Tartar." V Acad, anno 1703. 
In which Oil of Tartar there is much air by 
Experiment 74, which air was doubtlefs by 
its elafticity very inftrumental in the inflam- 
mability of this artificial fulphur. 

If Fire was a particular diftinft kind of 
body inherent in fulphur, as Mr. Homberg > 
Mr. Lemery, and fome others imagine, then 
fuch fulphureous bodies, when ignited, (hould 
rarefy and dilate all the circumambient air j 
whereas it is found by many of the precede- 


28 6 Analyfis of the Ah. 

ing Experiments, that acid fulphureous fuel 
conftantly attradts and condenfes a conlider- 
able part of the circumambient elaftick air ; 
An argument, that there is no fire endued 
with peculiar properties inherent in fulphur ; 
and alfo, that the heat of fire confifts princi- 
pally in the brisk vibrating aftion and re- 
action, between the elaftick repelling air, and 
the ftrongly attracting acid fulphur, which 
fulphur in its Analyfis is found to contain an 
inflammable oil, and acid fait, a very fix'd 
earth, and a little metal. 

Now fulphur and air are fuppofed to be 
afted by that ethereal medium, ' c by which 
" ( the great Sir Ifaac Newton fuppofes ) 
<c light is refradted and reflected, and by 
" whofe vibrations light communicates heat 
" to bodies, and is put into fits of eafy re- 
C£ fledtion, and eafy tranfmiffion : And do 
<c not the vibrations of this medium in hot 
<£ bodies contribute to the intenfenefs and 
<c duration of their heat? And do not hot 
<c bodies communicate their heat to conti- 
<c guous cold ones, by the vibrations of this 
<c medium, propagated from them into cold 
" ones ? And is not this medium exceed- 
" ingly more rare and fubtle than the air, 
" and exceedingly more elaftick and adive ? 

« And 

Analyjis of the Air. 287 
" And does it not readily pervade all bodies, 
<c Optic, qu. 18. The elaftick force of this 
" medium, in proportion to its denfity, muft 
u be above 490,000,000,000 times greater 
« than the elaftick force of the air is, in pro- 
u portion to its denfity, ibid.qu. 21." A force 
fufficient to give an intenfe degree of heat, 
efpecially when its elafticity is much increafed 
by the brisk aCtion and re-adlion of particles 
of the fuel and ambient air. 

From this manifeft attraction, aCtion and 
re-a&ion, that there is between the acid^ ful- 
phureous and elaftick aereal particles, we 
may not unreafonably conclude, that what 
we call the fire-particles in Lime 5 and feve- 
ral other bodies, which have undergone the 
fire, are the fulphureous and elaftick parti- 
cles of the fire fix'd in the Lime j which par- 
ticles, while the Lime was hot, were in a 
very a&ive, attracting and repelling ftatej 
and being, as the Lime cooled, detaiped in 
the folid body of the Lime, at the feveral at- 
tracting and repelling diftances they then hap- 
pended to be at, they muft neceffarily con- 
tinue in that fix'd ftate, notwithstanding the 
ethereal medium, which is fuppofed freely 
to pervade all bodies, be continually follicit- 
ing them to aCtion : But when the folid fub- 


-i 8 8 lUnalyfts of the Air. 
fiance of the Lime is difTolved, by the affu- 
fion of fome liquid, being thereby emanci- 
pated, they are again at liberty to be influ- 
enced and agitated by each others attraction 
and repulfion ; upon which a violent ebul- 
lition enfues, from the action and re-action 
of thefe particles; which ebullition ceafes 
not, till one part of the elaftick particles are 
fubdued and fix'd by the ftrong attraction 
of the fulphur, and the other part is got 
beyond the fphere of its attraction, and 
thereby thrown off into true permanent air: 
And that this is a probable folution of the 
matter, there is good reafon to conclude, 
from the frequent inftances we have in many 
of the foregoing Experiments, that plenty 
of elaftick air is at the fame time both gene- 
rated and abforbed by the lame fermenting 
mixture ; fome of which were obferved 
to generate more air than they abforbed, 
and others, e contra, abforbed more than 
they generated, which was the cafe of 

Experiment CXIX. 

And that the fulphureous and aereal par- 
ticles of the fire are lodged in many of thofe 


Analyfis of the Am 2 8 9 ' 

bodies which it ads upon, and thereby con- 
siderably augments their weight, is very evi- 
dent in Minium or Red Lead, which is ob- 
ferved to increafe in weight about JL part in 
undergoing the adion of the fire; the ac- 
quired rednefs of the Minium, indicating the 
addition of plenty of fulphur in the opera- 
tion : For fulphur, as it is found to ad: moil: 
vigouroufly on light, fo it is apt to refled 
the ftrongeft, viz. the red rays. And that 
there is good ftore of air added to the Mi- 
nium, I found by diftilling firft 1922 grains 
of Lead, from whence I obtained only feven 
cubick inches of air ; but from 1922 grains* 
which was a cubick inch of Red Lead, 
there arofe in the like fpace of time thirty- 
four cubick inches of air ; a great part of 
which air was doubtlefs abforbed by the 
fulphureous particles of the fuel, in the 
•reverberatory furnace, in » which the Mi- 
nium was made; for by Experiment 106. 
the more the fumes of a fire are confined, 
the greater quantity of elaftick air they ab- 

It was therefore doubtlefs this quantity 
of air in the Minium, which bur ft the her- 
metically fealed glaffes of the excellent Mr. 
Boyle, when he heated the Minium contain'd 

U in 

290 Analyjis of the Air. 

in them by a burning-glafs ; but the pious 
and learned Dr. Nieuwentyt attributes this 
effect wholly to the expanfion of the fire- 
particles lodged in the Minium, " he fup- 
" poling fire to be a particular fluid mat- 
" ter, which maintains its own effence and 
" figure, remaining always fire, though not 
cc always burning. Religious Philofopher, p. 
« 310." 

To the fame caufe alfo, exclufive of the 
air, he attributes the vaft expanfion of a 
mixture of compound Aqua-fortis and Oil of 
Carraways, whereas by Experiment 62. there 
is a great quantity of air in all Oils. And by 
pouring fome compound Aqua-fortis on Oil 
of Cloves, the mixture expanded into a fpace 
equal to 720 times the bulk of the oil y that 
part of the expanfion, which was owing to 
the watry part of the oil and fpirit, was foon 
contracted ; whereas the other part of the 
expanfion, which was owing to the elaftick 
air of the oil, w r as not all contracted till the 
next day, by which time the fulphureous 
fumes had reforbed it. 

It has been the opinion of fome, that pu- 
trefaction is the effect of inherent fire : that 
Vegetables alone are the fubject of Fermen- 
tation, but both Vegetables and Animals of 


Analyjis of the Air. 191 

putrefaction ; which operations they attri- 
bute to very different caufes. The immediate 
caufe of fermentation is (they fay) the mo- 
tion of the air intercepted between the fluid 
and vifcous parts of the fermenting liquors 
but the caufe of putrefaction they would 
have to be, fire itfelf, collected or included 
within the putrefying fubject. But I do not 
fee why thefe may not reafonably enough 
be looked upon as the effects of different 
degrees of fermentation ; nutrition being the 
genuine effect of that degree of it, in which 
the fum of the attracting action of the par- 
ticles is much fuperior to the fum of their 
repulfive power : But when their repelling 
force far exceeds their attractive, then the 
component parts of Vegetables are diflblved. 
Which diflblving fubflances, when they are 
diluted with much liquor, do not acquire a 
great heat in the diffblution, the brisknefs of 
the inteftine motion being checked by the 
liquor : But when they are only moift, like 
green and damp Hay, in a large heap, then 
they acquire a violent heat fo as to fcorch, 
burn and flame 5 whereby the union of their 
conftituent parts being more throughly dif- 
folved, they will neither produce a vinous, 
nor an acid fpirit : Which great degree of 
U 2 folution 

2 9 1 Analyfis of the Air. 

folution may well be effected by this means, 
without the a&ion of a fire, fuppofed to be 
included within the putrefying fubjedt. Where- 
fore, according to the old Axiom, Entia ?ion 
funt temere neque ahfque necejjitate multipli- 

If the notion of fermentation be reftrained 
to the greater repelling degrees of fermen- 
tation, in which fenfe it has commonly been 
underflood; then it is as certain, that the 
juices of Vegetables and Animals do not fer- 
ment in a healthy ftate, as it is, that they do 
not at the fame time coalefce and difunue : 
But if fermentation be taken in a larger {Qn(e y 
for any the fmalleft to the greatest degree 
of intefiine motion of the particles of a fluid, 
then all vegetable and animal fluids are in a 
natural (late, in fome degree of ferment; for 
they abound both with elaftick and fulphu- 
reous particles : And it may with as much 
reafon be argued, that there is no degree 
of warmth in Animals and Vegetables, be- 
caufe a great degree of heat will caufe a 
folution of continuity, as to fay, there is no 
decree of ferment in the fluids of thofe bo- 
dies, becaufe a great repelling degree of fer- 
ment will moil; certainly diffolve them. 


Analyjis of the An. 293 

That illuflrious Philofopher, Sir Tfaac New- 
ton, in his thoughts about the nature of acids, 
gives this rational account of the nature of 

fermentation. " The particles of acids 

" are endued with a great attractive force, 

" in which force their acYivitv confifts ■ 

" By this attractive force they get about the 
" particles of bodies, whether they be of a 
<c metallick or ftony nature, end adhere to 
" them moft clofely on all fides, fo that they 
cc can fcarce be feparated from them by diftil- 
u lation or fublimation 5 when they are at- 
cc traded and gathered together about the 
" particles of bodies, they raife, disjoin, and 
" make them one from another, that is, they 
" diffolve thofe bodies. 

" By their attractive force alio, by which 
" they rum towards the particles of bodies, 
" they move the fluid, and excite heat, and 
<c they make afunder fome particles, fo much 
<c as to turn them into air, and generate bub- 
" bles : And this is the reafon of diflblution, 
" and all violent fermentation. Harris's 
u Lexicon Tech. Vol. II. Introduction." 

Thus we have from thefe Experiments 
many manifefl proofs of confiderable quan- 
tities of true permanent air, which are by 
means of fire and fermentation raifed from, 
U 3 and 

294 dnalyjis of the Air. 
and abforbed by animal, vegetable and mine- 
ral fubftances. 

That this air confifts of particles which are 
in a very adtive ftate, repelling each other 
with force, and thereby conflituting the (lime 
kind of elaftick fluid with common air, is 
plain from its raifing the Mercury in Expe- 
riment 88 and 89, and from its continuing 
in that elaftick ftate for many months and 
years, tho' cool'd by fevere frofts j whereas 
watry vapours, tho* they expand much with 
heat, yet are found immediately to condenfe 
into their firft dimenfions when cold. 

The air generated by fire was not, in many 
inftances, feparated without great violence 
from the fix'd bodies, in which it was incor- 
porated ; as in the cafe of Nitre, Tartar, Sal 
Tartar and Copperas \ whence it ftiould feem, 
that the air generated from thefe Salts, may 
probably be very inftrumental in the union 
of Salts, as well as that central, denfer, and 
compacter particle of earth, which Sir Ifaac 
Newton obferves, does by its attraction make 
the watry acid flow round it, for compoling 
the particles of Salt, §w. 3 1. For fince, upon 
thediflblution of the conftituent parts of Salt 
by fire, it is found, that upon feparating and 
volatilizing the acid ipirit, the air-particles do 


Analyfis of the Ah. 295 

in great abundance rufh forth from a fixt to 
a repelling elaftick ftate ; it muft needs be, 
that thefe particles did, in their fixt ftate, 
ftrongly attradt the acid fpirits, as well as the 
fulphureous earthy parts of the Salt; for the 
moft ftrongly repelling and elaftick particles 
are obferv'd, in a fixt ftate, to be the moft 
ftrongly attracting. 

But the watry acid, which, when fepa- 
rated from Salt by the adtion of fire, makes 
a very corrofive fuming fpirit, will not make 
elaftick air, though its parts were put into a 
brisk motion by fire in Experiment 75. And 
the event was the fame with feveral other 
volatile fubftances, as volatile Salt of Sal 
Ammoniac, Camphire and Brandy; which, 
though diftilled over with a confiderable hear, 
yet generated no elaftick air, in Experiment 
52, 61, 66. Whence it is plain, the acid 
vapours in the air only float in it like the 
watry vapours ; and when ftrongly attra- 
cted by the elaftick particles of the air, 
they firmly adhere to them, and make 

Thus in Experiment 73. we fee, by the 

vaft quantity of air there is found in Tartar, 

that tho' it contains the other principles of 

vegetables, yet air, with fome volatile Salt, 

U 4 feems 

*9 6 Analyfn of the Ah. 

feems to make up a confiderable part of its 
compofition ; which air, when by the action 
of fire it is more firmly united with the earth, 
and acid fulphureous particles, requires a more 
intenfe degree of heat, to extricate it from 
thofe adhering fubftances, as we find in the 
diftillation of Sal Tartar, Exper. 74. which 
Air and volatile Salt are moft readily fepa- 
rated by fermentation. 

And by Experiment 72. plenty of air arifes 
alfo from Nitre, at the fame time that the 
acid fpirit is feparated from it by the action 
of fire. 

We find alfo by Experiment 71. that fome 
air is by the fame means obtained from com- 
mon Sea-fair, tho' not in fo great plenty, nor 
fo eafily, as from Tartar and Nitre, it being 
a more fixt body, by reafon of the fulphur 
which abounds in it; neither is it io eafily 
changed in animal bodies, as other Sales are; 
yet, fince it fertilizes ground, it muft needs be 
changed by vegetables. 

There is good reafon alfo to fufpedt, that 
thefe acid fpirits are not wholly free from 
air-particles, notwithstanding there were no 
elaftick ones produced, when they were put 
into a brick motion, by the action of fire in 
Experiment 75. which might be cccaficned 


Analyfis of the Air. 297 

by the great quantity of acid fpirit, in which 
they were involved. For we fee in Experi- 
ment 90. that when the acid fpirit of Aqua 
Regia was more ftrongly attracted by the 
diflblving gold, than by the air- particles, 
then plenty of air-particles, which were thus 
freed from the acid fpirit, did continually 
arife from the Aqua Regia, and not from the 
gold, at leaf! not from the metallick particles 
of the gold, for that lofes nothing of its 
weight in the folution ; fo that if any does 
arife from the gold, it muft be what may 
be latent in the pores of the gold. Whence 
it is probable, that the air which is obtained 
by the fermenting mixture of acid and alka- 
line fubftances, may not arife wholly from 
the diflblved alkaline body, but in part alfo 
from the acid. Thus the great quantity of 
elaflick air, which in Experiment 83. is gene- 
rated from the mixture of Vinegar and Oyfler- 
(hell, may as well arife in part from the Tar- 
tar, to which Vinegar owes its acidity, as 
from the diflblved Oyfterfhell. And what 
makes it further probable is, that the Vine- 
gar lofes its acidity in the ferment, that is, 
its Tartar: for diflblving menftruums are 
generally obferved to be changed in fermen- 
tation, as well as the diflblved body. 


ip8 Analyjls of the Air. 

Have we not reafon alfo hence to conclude, 
that the energy of acid fpirits may, in fome 
meafure, be owing to the ftrongly attracting 
air-particles in them; which adtive princi- 
ples may give an impetus to the acid Jpiculte, 
as well as the earthy oily matter, which is 
found in thefe acid fpirits? 

There are, we fee, alfo great ftore of air- 
particles found in the Analyfis of the blood, 
which arifes doubtlefs as well from the ferum 
as from the craffamentum^ for all the animal 
fluids and folids have air and fulphur in them : 
Which ftrongly attracting principles feem 
to be more intimately united together in the 
more perfect and elaborate part of it, its red 
glpbules; fo that we may not unreafonably 
conclude, that air is a band of union here as 
well as in Salts : And accordingly we find the 
greateft plenty of air in the mod folid parts 
of the body, where the cohefion of the parts 
is the ftrongeft -, for by comparing Experi- 
ment 49. and 51. we fee that much more air 
was found in the diftillation of horn, than of 
blood. And the cohefion of animal fubftances 
was nor, as we find by the fame Experiment, 
diflblved even in the blood, without confi- 
derable violence of fire ; tho' it is fometimes 
done to a fatal degree in our blood, by that 


AnaJyJis of the Air. 299 

more fubtile diffolvent fermentation: But we 
may obferve, that violent Salts, Spirits, and 
fulphureous Oil, which are at the fame time 
feparated from thefe fubftances, will not make 
elaftick air. 

Experiment CXX. 

As elaftick air is thus generated by the force 
of fire from thefe and many other fubftances, 
fo is the elafticity of the air greatly deftroyed 
by fulphureous bodies. Sir Ifaac Newton 
obferves, <c That as light acts upon fulphur, 
<c fo, fince all action is mutual, fulphurs ought 
" to acl: moil upon light." And the fame 
may be obferved of air and fulphur ; for by 
Experiment 103. it is found that burning 
fulphur, which is a very ftrongly attrad:ing 
fubftance, powerfully attracts and fixes the 
elaftick particles of air; fo that there muft 
needs be a good quantity of unelaftick air- 
particles in oil and flour of fulphur : The 
firft of which is made by burning fulphur 
under a bell, the other by fublimation : In 
further confirmation of this it is obferved, 
that Oleum Sulphuris per Campanam is with 
more difficulty made in a dry than a moift 
air ; and I have found by Experiment pur- 


500 Analyjis of the Air. 

pofely made, that a Candle, which burnt 70 " 
in a very dry receiver, burnt but 64" in the 
fame receiver, when filled with the fumes of 
hot water ; and yet abforbed one-fifth part 
more air, than when it burnt longer in the 
dry air. 

Sulphur not only abforbs the air when 
burning in a homogeneal mafs, but alfo in 
many fermenting mixtures ; and as Sir Ifaac 
Newton obferved the attractive and refractive 
power of bodies to be greater or lefs, as they 
partook more or lefs of fulphureous oily par- 
ticles -, fo there is good reafon from thefe Ex- 
periments to attribute the fixing of the ela- 
ftick particles of the air to the ftrong attra- 
ction of the fulphureous particles, with which 
he fays it is probable that all bodies abound 
more or lefs. Electrical bodies are alfo ob- 
ferved to attract more ftrongly, in proportion 
to the greater quantity of fulphur which they 

That great plenty of air is united with 
fulphur in the oil of vegetables, is evident, 
from the quantity of air that arofe from the 
diftillation of oils of Annifeeds and Olives, in 
Exper. 62. When by fermentation the con- 
ftituent parts of a Vegetable are feparated, 
part of the air flies off in fermentation into 


Analyfis of the Air. 301 
&n elaftick ftate; part unites with the eflen- 
tial Salt, Water, Oil and Earth, which con- 
ftitute the Tartar which adheres to the fides 
of the veffel ; the remainder, which continues 
in the fermented liquor, is there, fome of it 
in a fix'd, and fome in an elaftick ftate, which 
gives brisknefs to the liquor \ their expanding 
bubbles rifing of a very vifible fize, when the 
weight of the incumbent air is taken off the 
liquor in a vacuum. 

And as there was found a greater quantity 
of air in the deer's horn than in blood, we 
may alfo obferve it to be in a much greater 
proportion in the more folid parts of Vege- 
tables, than in their fluid : For we find in 
Experiment 55. $j. and 60. that near one- 
third part of the fubftance of the Peafe, heart 
of Oak, and Tobacco, were, by the adlion of 
fire, changed from an unelaftick ftate to an 
elaftick air : And fince a much greater pro- 
portion of air is found in the folid than the 
fluid parts of bodies, may we not with good 
reafon conclude, that it is very inftrumental, 
as a band of union in thofe bodies ? " Thofe 
" particles (as Sir Ifaac Newton obferves) 
ic receding from one another with the great- 
" eft repulfive force, and being moft diffi- 
*j cultly brought together, which upon con- 

" tadt 

3d AnaJyJis of the Air. 
" tacft cohere mod flrongly. <2>u. 3 1." And 
if the attraction of cohefion of an unelaftick 
air-particle be proportionable to its repulfive 
force in an elaftick ftate; then, fince its ela- 
ftick force is found to be fo vaftly great, fo 
mull that of its cohefion be alfo. Sir Ifaac 
Newton calculates from the inflexion of the 
rays of light, that the attracting force of par- 
ticles, near the point of contadt, is 10000, 
0000, 0000, 0000 greater than the force of 

Sulphur in a quiefcent fix'd ftate in a large 
body, does not abforb the elaftick air ; for a 
hard roll of Brimftone does not abforb air : 
But when fome of that Brimftone, by being 
powdered and mix'd with filings of Iron, is 
fet a fermenting, and thereby reduced into 
very minute particles, whofe attraction in- 
creafes as their fize decreafes ; then it abforbs 
elaftick air vigoroufly: As may be feen in 
many inftances under Experiment 95. The 
Walton Mineral, in which there is a good 
quantity of fulphur, did, when compound 
Aqua-fortis was poured on it, in Experiment 
96. make a confiderable fermentation, and 
abforb a great quantity of elaftick air : But 
when the ferment was much increafed, by 
adding an equal quantity of water to the like 


Analyjis of the Air. 305 

mixture, then inftead of abforbing 85 cubicle 
inches, as before, it generated 80 cubick 
inches of air : So that fermenting mixtures, 
which have fulphur in them, do not always 
abforb, but fometimes ^generate air: The 
reafon of which in the Experiment now under 
confideration feems to be this, viz. in the firft 
cafe a good quantity of elaftick air was gene- 
rated by the inteftine motion of the ferment- 
ing ingredients \ but there ariling thence a 
thick, acid, fulphureous fume, this fume ab- 
forbed a greater quantity of elaftick air than 
was before generated : And we find by Expe- 
riment 103, that the fulphureous particles 
which fly off in the air, do by their attra&ion 
deftroy its elafticity ; for in that Experiment 
burning Brimftone greatly deftroyed the air's 
elafticity -> which muft be done by the flame, 
and afcending fumes ; becaufe in the burning 
of any quantity of Brimftone the whole mafs 
is in a manner wafted, there remaining only a 
very little dry earth : And therefore the ab- 
forbed air cannot remain there, but muft be 
abforbed by the afcending fumes, which then 
attrafl: moft ftrongly, when reduced ad mi- 
nima : And it is well known, that a Candle in 
burning flies all off into flame and vapour, fo 
that what air it abforbs, muft be by thofe fumes. 


304 Analyjis of the Ah* 

Experiment CXXI. 

And further, I have found that thefe fumes 
deftroy the air's elafticity for many hours afcer 
the Brimftone Match, which made them, 
was taken out of the veflel z z a a: (Fig. 35.) 
Thofe fumes being firft cooled by immerfing 
that veflel and its ciftern x x y (or an inverted 
wine flask, full of the fumes) under cold wa- 
ter for fome time; then marking the furface 
of the water z z, I immerfed the veflels in 
warm water: And when all was cold again 
the following day, I found a good quantity 
of the air's elafticity was deftroy ed by the 
water's afcending above z z. And the event 
was the fame upon frequent repetitions of the 
fame Experiment. 

But if, inftead of the fumes of burning 
Brimftone, I filled a flask full of fumes from 
the fmoak of wood, after it had done flame- 
ing, then there was but half as much air 
abforbed by thofe fumes, as there was by 
the fumes of Brimftone ; viz. becaufe the 
fmoak of wood was much diluted with the 
watry vapour which attended with it out 
of the wood. And this is doublefs the rea~ 
fon why the fmoak of wood, though it in- 

Analyjis of the Air. 305 

commodes the lungs, yet it will not fuffocate 
like that of Charcoal, which is withal more 
fulphureous, without any mixture of watry 

And that new generated elaftick air is re- 
forbed by thefe fumes, I found by attempting 
to fire a Match of Brimftone with a burning- 
glafs, by means of a pretty large piece of 
Brown Paper, which had been dipped in a 
ftrong folution of Nitre, and then dried ; 
which Nitre indetonizing generated near tw r o 
quarts of air; which quantity of air, and a 
great deal more, was abforbed, when the 
Brimftone took fire, and flamed vigoroufly. 

So that the 85 cubick inches of air, Exper. 
96. which I found upon meafuring, was ab- 
forbed by the Walton Mineral and compound 
Aqua-fortiS) was the excefs of what was ab- 
forbed by thofe fumes above what was gene- 
rated by the fermenting mixture. 

And the reafon is the fame in Filings of 
Iron, and Spirit of Nitre, Exper. 94. which 
alfo abforbed more than they generated, whe- 
ther with or without water. 

Hence alfo we fee the reafon why Filings 
of Iron and compound Aqua-fortis> in the 
fame 94th Experiment, abforbed air $ and why, 
when mix'd with an equal quantity of water, 

X it 

]o6 Analyjis of the Air. 

it moftly abforbed, but did fometimes gene- 
rate, and then abforb again : And it was the 
fame with oil of Vitriol, filings of Iron and 
Water, and N ewe aft I e Coal, and compound 
Aqua-fortis, and others : viz. At firft, when 
the ferment was brisk, the abforbing fumes 
rofe fafteft, whereby more air was abforbed 
than generated ; but as the ferment abated, to 
fiich a degree as to be able ftill to generate 
elaftick air, but not to fend forth a propor- 
tionable quantity of fumes, in that cafe more 
air would be generated than abforbed. 

And in Experiment 95. there are feveral 
inftances of the air's being in like manner ab- 
forbed in lefler degrees, by other fermenting 
mixtures : As in the mixture of fpirit of Harts- 
horn with filings of Iron, and with filings of 
Copper : And fpirit of Sal Ammoniac with 
filings of Copper ; and alfo filings of Iron 
and Water $ powdered Flint, and compound 
Aqua-fvrth \ powdered Brijlol Diamond with 
the fame liquor. 

It is probable from Experiment 103 and 
106. where it was found that the thicker 
the fuliginous vapours were, the fafter they 
abforbed the air, that if the above-mentioned 
fermenting mixtures had not been confined 
in clofe velTels, but in the open air, where 


Analyfis of the Ah. 307 

the vapours would have been lefs denfe, that 
in that cafe much lefs air would have been 
abforbed, perhaps a great deal lefs than wa9 

In the fecond cafe of the Walton Mineral, 
Experiment 96. when inftead of abforbing, 
it generated air, the parts of the compound 
Aqua-fortis were then more at liberty to ad: 
by being diluted with an equal quantity of 
water 5 whereby the ferment being more 
violent, the particles which conftituted the 
new elaftick air were thereby thrown off in 
greater plenty, and perhaps with a greater 
degree of elafticity, which might carry them 
beyond the fphere of attraction of the ful- 
phureous particles. 

This is further illuftrated by Experiment 
94. where filings of Iron and oil of Vitriol 
alone generated very little, but the like quan- 
tities of filings of Iron, with an equal quan- 
tity of water, generated 43 cubick inches of 
air; and the like ingredients, with three times 
that quantity cf water, generated 108 cubick 

And though the quantity of the afcending 
fumes (which was in this cafe of the Walton 
Mineral very great) mull needs in their afcent 
abforb a good deal of elaftick air, (for they 

X 2 will 

3 o 8 Analyfis of the Air. 

will abforb air) yet if, where the ferment was 
(o much greater, more elaftick air was gene- 
rated by the fermenting mixture, than was 
abforbed by the afcending fumes, then the 
quantity of new generated air, which I found 
between zz and aa^ (Fig. 35.) when I mea- 
fured it, was equal to the excefs of what was 
generated above what was abforbed. 

And probably in this cafe the air was not 
abforbed fo much in proportion to the den- 
fity of the fumes, as in the firft cafe ; becaufe 
here the fulphureous fumes were much 
blended with w r atry vapours : for we find in 
Experiment 97. that fix times more was 
wafted in fumes in this cafe, than in the 
other ; and therefore probably a good part 
of the cubick inch of water afcended with 
the vapour, and might thereby weaken its 
abforbing power : For watry vapours do not 
abforb elaftick air as the fulphureous ones do ; 
tho' by Experiment 12,0. a Candle abforbed 
more in a damp than in a dry air. 

And it is from thefe diluting watry vapours, 
that filings of Iron, with fpirit of Nitre and 
Water, abforbed lefs than with fpirit of Nitre 
alone -, for in both cafes it abforbs more than 
it generates. 


Analyjis of the Air. 3 09 

Thus alfo oil of Vitriol and Chalk gene- 
rate air, their fume being fmall, and that 
much diluted with the watry vapours in the 

But Lime, with oil of Vitriol, or White- 
Wine Vinegar or Water, make a confiderable 
fume, and abforb good quantities of air : 
Lime alone left to flaken gradually, as it 
makes no fume, fo it abforbs no air. 

We fee in Experiment 92. where the fer- 
ment was not very fudden nor violent, nor 
the quantity of abforbing fumes large, that 
the Antimony and Aqua-fort is generated a 
quantity of air equal to 520 times the bulk 
of the Antimony. Thus alfo in the mixture of 
Aqua Regia and Antimony, in Experiment 
91. while at firft the ferment was fmall, then 
air was generated ; but when with the in- 
creafing ferment plenty of fumes arofe, then 
there was a change from a generating to an 
abforbing ftate. , See Vol. II. ^.292. 

Since we find fuch great quantities of ela- 
ftick air generated in the folution of animal 
and vegetable fubftances, it muft needs be, 
that a good deal does conftantly arife from 
the diflblving of thefe aliments in the flomach 
and bowels, which diffolution it greatly pro- 
motes : Some of which may very probably 
X 3 be 

3 i o dnalyfis of the Ah. 
be reforbed again, by the fumes which arife 
with them; for we fee in Experiment 83. 
that Oyfter-fhell and Vinegar, Oyfter-fhell 
and Rennet, Oyfter-fhell and Orange-juice, 
Rennet alone, Rennet and Bread, firft gene- 
rated, and then abforbed air ; but Oyfter-fhell 
withfome of the liquor of a Calf's ftomach, 
which had fed much upon Hay, did not gene- 
rate air; and it was the fame with Oyfter-fhell 
and Ox-gall, and Spittle and Urine ; Oyfter- 
fhell and Milk generated a little air, but Li- 
rncn-juice and Milk did at the fame time ab- 
forb a little : Thus we fee, that the variety of ' 
mixtures in the ftomach appear fometimesto 
generate, and fometimes to abforb air ; that 
is, there is fometimes more generated than 
abforbed, and fometimes an equal quantity, 
and fometimes lefs, according to the propor- 
tion the generating power of the diflblving 
aliments bears to the abforbing power of the 
fumes which arife from them. In a true 
kindly digeftion, the generating power exceeds 
the abforbing power but a little : But when- 
ever the digeftion deviates in fome degree 
from this natural ftate, to generate a greater 
proportion of elaftick air, then are we trou- 
bled more cr lefs with diftending Flatus's. I 
had intended to make thefe, and many more, 


dnalyfis of the Air. 311 

Experiments, relating to the nature of dige- 
stion, in a warmth equal to that of the fto- 
mach ; but have been hitherto prevented by 
purfuing other Experiments. 

Thus we fee that all thefe mixtures do in 
fermentation generate elaftick air; but thofe 
which emit thick fumes, charg'd with ful- 
phur, reforb more than was generated, in pro- 
portion to the fulphureoufnefs and thicknefs 
of thofe fumes. 

I have alfo fhewn in many of the forego- 
ing Experiments, that plenty of true perma- 
nent elaftick air is generated from the fer- 
menting mixtures of acid and alkaline fub- 
ftances, and efpccially from the fermentation 
and difTolution of animal and vegetable bo- 
dies, into whofe fubftances we fee it is in a 
great proportion intimately and firmly incor- 
porated; and confequcntly great quantities of 
elaftick air muft be continually expended in 
their production; part of which does, we fee, 
refume its elaftick quality, when briskly 
thrown off from thofe bodies by fermentation 
in the difTolution of their texture. But part 
may probably never regain its elafticity, or at 
leaft not in many centuries, that efpecially 
which is incorporated into the more durable 
parts of Animals and Vegetables. However, 

X 4 we 

3 i 1 dnaljfis of the AiY. 

we may with pleafure fee what immenfe trea- 
fures of this noble and important element, 
endued with a moft active principle, the all- 
wife Providence of the great Author of na- 
ture has provided, the conftant wafle of it 
being abundantly fupplied by heat and fer- 
mentation from innumerable denfe bodies ; 
and that probably from many of thofe bodies, 
which, when they had their afcending fumes 
confined in my glafTes, abforbed more air 
than they generated ; but would, in a more 
free, open fpace, generate more than they ab- 

I made fome attempts both by fire, and 
alio by fermenting and abforbing mixtures, 
to try if I could deprive all the panicles of 
any quantity of elaftick air of their elaflicity • 
but I could not effect it : There is therefore 
no direct proof from any of thefe Experi- 
ments, that all the elaftick air may be ab- 
forbed, tho' 'tis very probable it may, fince 
we find it is in fuch great plenty generated 
and abforbed \ it may well therefore be all 
abforbed and changed from an elaftick to a 
fixe ftate : For, as Sir Is a a c Newto n 
obferves of light, " That nothing more is re- 
•* quifite for producing all the variety of co~ 
•' lour:, and degrees of refrangibiliiy, than 

" that 

Analyfis of the Air. 3 1 3 

« that the rays of light be bodies of different 
" fizes, the lead of which may make the 
" weakeft and darkeft of the colours, and be 
" more eafily diverted, by refracting furfaces 
<f from the right courfej and the reft, as 
cr they are bigger and bigger, may make the 

<c ftronger and more lucid colours and be 

" more and more difficultly diverted, ^u t 29." 
So %u. 30. he obferves of air, " That denfe 
f< bodies, by fermentation, rarefy into feveral 
" forts of air, and th : s air, by fermentation, 
" and fometimes without, returns into denfe 
u bodies. And fince we find in fadl from 
thefe Experiments, that air arifes from a 
great variety of denfe bodies, both by fire 
and fermentation, it is probable that they 
may have very different degrees of elafticity, 
in proportion to the different fize and denfity 
of i:s particles, and the different force with 
vyhich they were thrown off into an elaftick 
date. " Thofe particles (as Sir Isaac New- 
<c ton obferves) receding from one another, 
" with the greateft repulfive force, and being 
M moft difficultly brought together, which 
" upon contad: cohere mod ftrongly. " 
Whence thofe of the weakeft elafticity will 
be leaft able to refill a counter-ailing power, 
and will therefore be fooneft changed from 


3 1 4 Analyjis of the Air. 

an elaftick to a fixt flate. And 'tis confonant 
to reafon to think, that the air may confift 
of infinite degrees of thefe, from the moft 
elaftick and repelling, till we come to the 
more fluggifh, watry, and other particles, 
which float in the air; yet the repelling force 
of the leaft elaftick particle, near the furface 
of the earth, while it continues in that ela- 
ftick ftate, muft be fuperior to the incumbent 
preflure of a column of air, whofe height is 
equal to that of the atmofphere, and its bafe 
to the furface of the fphere of its elaftick 

Thus, upon the whole, we fee that air 
abounds in animal, vegetable, and mineral 
fubftances -, in all which it bears a consider- 
able part : if all the parts of matter were 
only endued with a ftrongly attra&ing power, 
whole nature would then immediately be- 
come one unadtive cohering lump $ where- 
fore it was abfolutely neceflary, in order to 
the actuating and enlivening this vaft mafs of 
attracting matter, that there fhould be every 
where intermix'd with it a due proportion 
of ftrongly repelling elaftick particles, which 
might enliven the whole mafs, by the incef- 
fant aftion between them and the attracting 
particles : And fince thefe elaftick particles 


Analyjis of the Air. 315 

are continually in great abundance reduced 
by the power of the ftrong attradters, from an 
elaftick to a fixt ftate ; it was therefore ne- 
ceflary, that thefe particles fhould be endued 
with a property of refuming their elaftick 
ftate, whenever they were difengaged from 
that mafs in which they were fixt, that thereby 
this beautiful frame of things might be main- 
tained in a continual round of the produ- 
ction and difiblution of animal and vegetable 

The air is very inftrumental in the pro- 
duction and growth of animals and vegeta- 
bles, both by invigorating their feveral juices 
while in an elaftick acftive ftate, and alfo by 
greatly contributing in a fix'd ftate to the 
union and firm connection of the feveral con- 
ftiment parts of thofe bodies, viz. their wa- 
ter, fait, fulphur, and earth. This band of 
union, in conjunction with the external air, 
is alfo a very powerful agent in the diffolu- 
tion and corruption of the fame bodies; for 
it makes one in every fermenting mixture ; 
the action and re-a&ion of the aereal and ful- 
phureous particles is, in many fermenting 
mixtures, fo great, as to excite a burning 
heat, and in others a fudden flame : And it 
is, we fee, by the like a&ion and re-aCtion 


3 1 6 • Jnalyjis of the AW. 

of the fame principles, in fuel and the am- 
bient air, that common culinary fires are pro- 
duced and maintained. 

Tho' the force of its elafticity is fo great 
as to be able to bear a prodigious preflure> 
without lofing that elafticity, yet we have, 
from the foregoing Experiments, evident 
proof, that its elafticity is eafily, and in great 
abundance deftroyed ; and is thereby reduced 
to a fixt ftate, by the ftrong attraction of the 
acid fulphureous particles, which arife either 
from fire or from fermentation : And there- 
fore elaflicity is not an ejfential immutable 
property of air-particles ; but they are, we fee, 
eafily changed from an elaftick to a fixt ftate, 
by the ftrong attraction of the acid, fulphu- 
reous, and faline particles, which abound in 
the air. Whence it is reafonable to conclude, 
that our atmofphere is a Chaos, confifting 
not only of elaftick, but alfo of unelaftick 
air-particles, which in great plenty float in it, 
as well as the fulphureous, faline, watry and 
earthy particles, which are no ways capable 
of being thrown off into a permanently ela- 
ftick ftate, like thofe particles which confti- 
ftute true permanent air. 

Since then air is found fo manifeftly to 
abound in almoft all natural bodies ; fince we 


Analyfis of the Air. 3 17 
find it fo operative and aftive a * principle in 
every chymical operation ; fince its constituent 
parts are of fo durable a nature, that the 
moft violent aftion of fire or fermentation 
cannot induce fuch an alteration of its texture, 
as thereby to difqualify it from refuming, 
either by the means of fire, or fermentation, 
its former elaftick ftate > unlefs in the cafe of 
vitrification, when, with the vegetable Salt 
and Nitre, in which it is incorporated, it 
may perhaps fome of it, with other chymical 
principles, be immutably fixt: Since then 
this is the cafe, may we not with good reafon 
adopt this now fixt, now volatile Proteus, 
among the chymical principles, and that a 
very aftive one, as well as acid fulphur 5 not- 
withstanding it has hitherto been overlooked 
and rejedted by Chymifls, as no way intitled 
to that denomination ? 

If thofe who unhappily fpent their time 
and fubftance in fearch after an imaginary 
production, that was to reduce all things to 
gold, had, inftead of that fruitlefs purfuit, be- 
llowed their labour in fearching after this 
much negle&ed volatile Hermes, who has fo 
often efcaped thro' their burft receivers, in 

* Jonjls omnia plena, Virgil, 


3 1 8 Of Vegetation. 

the difguife of a fubtile fpirit, a mere flatu- 
lent explofive matter; they would then, in- 
ftead of reaping vanity, have found their 
refearches rewarded with very confiderable 
and ufeful difcoveries. 



Of Vegetation. 

WE are but too fenfible, that our rea- 
fonings about the wonderful and in- 
tricate operations of nature are fo full of un- 
certainty, that, as the Wife- man truly ob- 
ferves, hardly do me guefs aright at the things 
that are upon earth, and with labour do we 
find the things that are before us. Wifdom, 
Chap. ix. ver. 16. And this obfervation we 
find fufhciently verified in vegetable nature, 
whofe abundant productions, tho' they are 
moft vifible and obvious to us, yet are we 
much in the dark about the nature of them; 
becaufe the texture of the veffels of plants is 
fo intricate and fine, that we can trace but 
few of them, though affifted with the beft 
microfcopes. We have however good reafon 



Of Vegetation. 3 19 

to be diligent in making farther and farther 
refearches -, for tho' we can never hope to 
come to the bottom and firft principles of 
things, yet in fo inexhauftible a fubjed:, where 
every the fmalleft part of this wonderful fa- 
brick is wrought in the moft curious and 
beautiful manner, we need not doubt of have- 
ing our inquiries rewarded, with fome fur- 
ther pleafing difcovery ; but if this fhould 
not be the reward of our diligence, we are 
however fure of entertaining our minds after 
the moft agreeable manner, by feeing in every 
thing, with furprizing delight, fuch plain 
fignatures of the wonderful hand of the Di- 
vine Architect, as muft neceffarily difpofe and 
carry our thoughts to an adt of adoration, the 
beft and nobleft employment and entertain- 
ment of the mind. 

What I (hall here fay, will be chiefly found- 
ed on the following Experiments; and on 
feveral of the preceding ones, without repeat- 
ing what has already been occafionally ob» 
ferved on the fubjed: of Vegetation. 

We find by the chymical Analyfis of Vege- 
tables, that their fubftance is compofed of 
fulphur, volatile fait, water and earth ; which 
principles are all endued with mutually at- 
tracting powers, and alfo of a large portion 


320 Of Vegetation. 

of air, which has a wonderful property of 
ftrongly attracting in a fixt ftate, or of re- 
pelling in an elaftick ftate, with a power 
which is fuperior to vaft compreffing forces 3 
and it is by the infinite combinations, action 
and re-action of thefe principles, that all the 
operations in animal and vegetable bodies are 

Thefe active aereal particles are very fer- 
viceable in carrying on the work of Vege- 
tation to its perfection and maturity ; not 
only in helping by their elafticity to diftend 
each ductile part, but alfo by enlivening and 
invigorating their fap, where, mixing with 
the other mutually attracting principles, they 
are by gentle heat and motion fet at liberty 
to affimilate into the nourifhment of the re- 
fpective parts : " The foft and moift nourifh- 
11 ment eafily changing its texture by gentle 
< c heat and motion, which congregates homo- 
cc geneal bodies, and feparates heterogeneal 
<c ones." Ncwtoris Opticks y qu. 31. The 
fum of the attracting power of thefe mutu- 
ally acting and re-acting principles being, 
while in this nutritive ftate, fuperior to the 
fum of their repelling power 5 whereby the 
work of nutrition is gradually advanced 
by the nearer and nearer union of thefe 


Of Vegetation. 3 1 1 

principles, from a leffer to a greater degree 
of confiftency, till they are advanced to that 
vifcid ductile ftate, whence the feveral parts 
of Vegetables are formed -, and are at length 
firmly compared into hard fubftances, by 
the flying off of the watry diluting vehicle, 
fooner or later, according to the different de- 
grees of cohefion of thefe thus compacted 

But when the watry particles do again foak 
into and difunite them, and their repelling 
power is thereby become fuperior to their 
attracting power 5 then is the union of the 
parts of Vegetables thereby fo thoroughly dif- 
folved, that this ftate of putrefaction does i 
by a wife order of Providence, fit them to re- 
fufcitate again in new vegetable productions, 
whereby the nutritive fund of nature can ne- 
ver be exhaufted ; which being the fame both 
in Animals and Vegetables, it is thereby ad- 
mirably fitted, by a little alteration of its tex- 
ture, to nourifh either. 

Now, tho' all the principles of Vegetables 
are, in their due proportion, neceflary to the 
production and perfection of them ; yet we 
generally find greater proportions of oil in 
the more elaborate and exalted parts of Vege- 
tables : And thus feeds are found to abound 

Y with 

311 Of Vegetation. 

with oil, and confequently with fulphur and 
air, as we fee by Experiment 56. $j. 58. 
Which feeds containing the rudiments of 
future Vegetables, it was neceflary that they 
fhould be well ftored with principles that 
would both preferve the feed from putre- 
faction, and alfo be very active in promoting 
Germination and Vegetation. Thus alfo by 
the grateful odours of flowers we are allured, 
that they are ftored with a very fubtile, highly 
fublimed oil, which perfumes the ambient 
air ; and the fame may be obferv'd from the 
high taftes of fruits. 

And as Oil is an excellent prefervative 
againft the injuries of cold, fo it is found 
to abound in the fap of the more northern 
trees; and it is this which in Ever-greens 
keeps their leaves from falling. 

But plants of a lefs durable texture, as 
they abound with a greater proportion of 
fait and water, which is not fo ftrongly at- 
tracting as fulphur and air, fo are they lefs 
able to endure the cold; and as plants are 
obferved to have a greater proportion of fak 
and water in them in the fpring, than in 
the autumn, fo are they more eafily injured 
by cold in the fpring, than in a more ad- 

Of Vegetation. 323 

vanced age, when their quantity of oil is in- 
creafed wich their greater maturity. 

Whence we find that Nature's chief bufi- 
iiefs in bringing the parts of a Vegetable, efpe- 
cially its fruit and feed, to maturity, is to com- 
bine together in a due proportion, the more 
active and noble principles of fulphur and air, 
that chiefly conftitute oil, which in its moft 
refined ftate is never found without fome de- 
gree of earth and fait in it. 

And the more perfect this maturity is, the 
more firmly are thefe noble principles united. 
Thus Rhenifh Wines, which grow in a more 
northern climate, are found to yield their 
Tartar, u e. by Exper.73. their incorporated 
air and fulphur, in greater plenty* than the 
ftronger Wines of hotter countries, in which 
thefe generous principles are more firmly 
united : And particularly in Madeira Wine, 
they are fixt to fuch a degree, that that Wine 
requires a confiderable degree of warmth, 
fuch as would deftroy the more delicate tex- 
ture of many other Wines, to keep it in order, 
and give it a generous tafte 5 and 'tis from 
the fame reafon, that fmall French Wines are 
found to yield more fpirit in diftillation, than 
ftrong Spanijh Wines, 

Y 2 But 

324 Of Vegetation. 

But when, on the other hand, the crude 
watry part of the nutriment bears too great a 
proportion to the more noble principles either 
in a too luxuriant ftate of a plant, or when 
its roots are planted too deep, or it ftands in 
too fhady a pofition, or in a very cold and wet 
fummer; then it is found, that either no 
fruit is produced, or if there be any, yet it 
continues in a crude watry flate 3 and never 
comes to that degree < f maturity, which a 
due proportion of the more noble principles 
would bring it to. 

Thus we find in this and every other part 
of this beautiful fcene of things, w T hen we 
attentively eoniider them, that the great Au- 
thor of nature has admirably tempered the 
conftituent principles of natural bodies, in 
fuch due proportions as might befl fit them 
for the flate and purpoles they were intended 

It is very plain from many of the foregoing 
Experiments and Obfervations, that the leaves 
are very ferviceable in this work of Vegeta- 
tion, by being inflrumental in bringing nou- 
rishment from the lower parts, within the 
reach of the attraction of the growing fruit; 
which, like young animals, is furnifhed with 
proper inftruments to fuck it thence, But 


Of Vegetation. 325 

the leaves feem alfo defigned for many other 
noble and important fcrvices ; for Nature 
admirably adapts her iuflruments fo as to 
be at the fame time ferviceabie to many 
good purpoies. Thus the leaves, in which 
are the main excretory ducts in Vegetables, 
feparate and carry off the redundant watry 
fluid, which by being long detained, would 
turn rancid and prejudicious to the plant, 
leaving the more nutritive parts to coalefce ; 
part of which nourifhmenr, we have good 
reafon to think, is conveyed into Vegetables 
through the leaves, which do plentifully im- 
bibe the dew and rain, which contain fait, 
fulphur, &c. For the air is full of acid 
and fulphureous particle?, which when they 
abound much, do, by the action and re-action 
between them and the elaiiick air, cauie that 
fultry heat, which ufually ends in lightning 
and thunder : And thefe new combinations 
of air, fulphur, and acid fpirit, which are 
constantly forming in the air, are doubtlefs 
very ferviceabie in promoting the work of 
Vegetation ; when being imbibed by the 
leave?, they may not improbably be the 
materials out of which the more fubtile and 
refined principles of Vegetables are formed : 
For fo fine a fluid as the air ieems to be a 

Y 3 more 

^i6 Of Vegetation. 

more proper medium, wherein to prepare 
and combine the more exalted principles of 
Vegetables, than the groffer watry fluid of 
the fap; and for the fame reafon, 'tis likely, 
that the moft refined and adlive principles 
of Animals are alfo prepared in the air, and 
thence conveyed through the lungs into the 
blood ; and that there is plenty of thele 
fulphureo-aereal particles in the leaves, is 
evident from the fulphureous exudations, 
which are found at the edges of leaves, 
which Bees are obierved to make their waxen 
cells of, as well as of the duft of flowers: 
And that wax abounds with fulphur i$ plain, 
from its burning freely, &c. 

We may therefore reafonably conclude, 
that one great ufe of leaves is what has been 
long fufpe&ed by many, viz. to perform in 
fome meafure the fame office for the fup- 
port of the vegetable life, that the lungs of 
Animals do, for the fupport of the animal 
life 5 Plants very probably drawing through 
their leaves fome part of their nourifhment 
from the air. 

But as plants have not a dilating and con- 
tracing 'Thorax, their infpirations and expi- 
rations will no: be fo frequent as thofe of 
^nirnals, but depend wholly on the alter- 

Of Vegetation. 327 

nate changes from hot to cold for inspira- 
tion, and vice verfa for expiration ; and 'tis 
not improbable, that plants of more rich and 
racy juices may imbibe and affimilate more 
of this aereal food into their conftitutions, 
than others, which have more watry vapid 
juices. We may look upon the Vine as a 
good inftance of this, which in Experiment 
3. perfpired lefs than the Apple-tree. For 
as it delights not in drawing much watry 
nourishment from the earth by its roots, fo 
it mud therefore neceffarily be brought to a 
more ftrongly imbibing ftate at night, than 
other trees, which abound more with watry 
nourifhment ; and it will therefore confe- 
quently imbibe more from the air. And 
likely this may be the reafon, why plants in 
hot countries abound more with fine aro- 
matick principles, than the more northern 
plants; for they do undoubtedly imbibe more 

And if this conjecture be right, then it 
gives us a farther reafon, why trees which 
abound with moifture, either from too 
(haded a pofition, or a too luxurious flare, 
are unfruitful, viz. becaufe, being in theie 
cafes more replete with moifture, they can- 
not imbibe fo ftrongly from tht air, as 

Y 4 Others 

3 1 8 Of Vegetation. 

others do, that? great bleffing, the dew oi 

And as the moft racy generous taftes of 
fruits, and the grateful odours of flowers, 
do not improbably arife from thefe refined 
aereal principles, fo may the beautiful colours 
of flowers be owing, in a good meafure, to 
the lame original ; for it is a known obfer- 
vation, that a dry foil contributes much more 
to their vaiiegation, than a ftrong moift one 

And may not Light alfo, by freely entring 
the expanded furfaces of leaves and flowers, 
contribute much to the ennobling the prin- 
ciples of Vegetables ? For Sir Ifaac Newton 
puts it as a very probable query, c: Are not 
cc grofs bodies and Light convertible into 
" one another ? And may not bodies receive 
c< much of their activity from the particles 
cc of Light, which enter their competition ? 
" The change of bodies into light, and of 
" light into bodies, is very conformable to 
u the courfe of nature, which feems delighted 
c ' with tranfmutations, Opt. %u. 30." 


Of Vegetation. 319 

Experiment CXXII. 

That the Leaves and Stems of Plants do 
imbibe elaftick air, there is fome reafon to 
fufpedt, from the following Experiment, 
which, in the firft Edition of this Book, I 
mentioned as not made with accuracy enough; 
but I have iince repeated it with greater ac- 
curacy, viz, June 29. I fet a well-rooted 
plant of Pepper-mint in a glafs-ciftern full of 
earth, and then poured in as much water as 
it would contain ; over this glafs-ciftern I 
placed an inverted glafs z z y a a y as in Fig. 
35. the water being drawn up by means of 
a fyphon to a a. At the fame time alfo I 
placed in the fame manner another inverted 
glafs z z, a a, of equal fize with the former, 
but without any plant under it: the capacity 
of thefe veiTels above the water a a was equal 
to 49 cubick inches. In a month's time the 
Mint had made feveral weak flender fhoots, 
and many fmall hairy roots fliot out at the 
joints that were above water, occaiioned pro- 
bably by the great moifture of the air, in 
which the plant flood ; half the leaves of the 
old item were now dead ; but the leaves and 
|lem of the young (hoots continued green 


3 3 o Of Vegetation. 

mod part of the following winter: The wa- 
ter in the two inverted 'glaffes rofe and fell, 
as ic was either affefted by the different 
weight of the Atmofphere, or by the dila- 
tation and contraction of the air above a a. 
But the w r ater in the veffel in which the 
Pepper-mint flood, rofe fo much above a a, 
and above the furface of the water in the 
other veffel, that one-feventh part of that 
air mud have been reduced to a fixe ftate, 
either by being imbibed into the fubftance 
of the plant, or by the vapours which arofe 
from the plant. This was chiefly done in 
the two or three fummer months; for after 
that no more air was abforbed. The begin- 
ning of April in the following fpring, I took 
out the old mint, and put a frefli plant in 
its place, to try if ic would abiorb any 
more of the air, but it faded in four or five 
days. Yet a frefli plant put into the other 
glafs, w r hofe air had been confined for nine 
months, lived near a month, almoft as long 
as another plant did in frefli confined air; 
for I have found that a tender plant confined 
in this manner in April, would not live fo 
long as a ftronger grown plant, put in in 


Of Vegetation. 331 

The like plants placed in the fame man- 
ner feparately, in the diftilled airs of Tartar 
and Newcajlle Coal y foon faded ; yet a like 
plant confined in three pints of air, a quart 
of which was diftilled from an Ox's tooth, 
grew about two inches in height, and had 
fome green leaves on it, after fix or feven 
weeks confinement. 

Finding that a frefh plant could not live 
in the air, which had been for feveral months 
infected by the mint which was placed in it 
the 19th oijune ; inftead of a plant, I placed 
in that air a mixture of powdered Brimftone 
and filings of Iron moiftened with water ; this 
mixture abforbed four cubick inches of this 

Experiment CXXIII. 

In order to find out the manner of the 
growth of young fhoots, I firft prepared the 
following inftrument ; viz. I took a fmall 
flicks, (Fig. 40.) and at a quarter of an inch 
diftance from each other, I run the points of 
five pins, 1, 2, 3, 4, 5, thro' the flick, fo far 
as to ftand-J of an inch from the flick; then 
bending down the great ends of the pins, I 
bound them all faft with waxed thread ; I 
provided alio fome red-lead mixed with oil. 


3 5 x Of Vegetation. 

In the fpring, when the Vines had made 
fhort fhoots, I dipped the points of the pins 
in the paint, and then pricked the young 
fhoot of a Vine (Fig. 41.) with the five 
points at once, from t to p : I then took 
off the marking inftrumenr, and placing the 
low.-ft point of it in the hole p, the upper- 
mod mark, I again pricked frefli holes from 
p to /, and then marked the two other points 
i h \ thus the whole (hoot was marked every 
JL inch, the red paint making every point 
remain vifible. 

(Fig. 42.) {hews the true proportion of 
the fame {hoot, when it was full grown; 
the September following ; where every cor- 
refponding point is noted with the fame 

The diftance from / to j was not en- 
larged above 3— part of an inch ; from s to q, 
the -£ of an inch ; from q to p, | ; from p 
to 0, j ; from to tf, tf; from n to m y if; 
from m to /, 1 *\- T £ of an inch ; from / to /, 
1 + to inch nearly j and from i to l\ three 

In this Experiment we fee, that the firft 
joint to r extended very little, it being al- 
nioft hardened, and come near to its full 
growth, when I marked it: The next joint, 


Of Vegetation. 333 

from r to ;/, being younger, extended fome- 
thin<* more ; and the third joinr, from n to k, 
extended from | of an inch, to 3 + i inches ; 
but from k to h> the very tender joint, which 
was but \ inch long, when I marked it, was, 
when full grown, three inches long. 

We may obferve, that Nature, in order 
to fupply thefe young growing {hoots with 
plenty of ductile matter, is very careful to 
furnifh, at fmall diftances, the young /hoots of 
all forts of trees with many leaves throughout 
their whole length, which ferve as fo many 
jointly acting pov/ers placed at different fta- 
tions, thereby to draw with more eafe plenty 
of fap to the extending {hoot. 

The like provilion has Nature made in 
the Corn, Grafs, Cane, and Reed-kind ; the 
leafy fpires, which draw the nourishment to 
each joint, being provided long before the 
ftem (hoots ; which {lender ftem, in its ten- 
der ductile ftate, would moft eafily break, 
and dry up too foon, fo as to prevent its due 
growth, had not Nature, to prevent both 
thefe inconveniencies, provided ftrong Thecas 
or Scabbards, which both fupport and keep 
long, in a fupple ductile ftate, the tender 
extending ftem. 

354 Of Vegetation. 

I marked in the fame manner as the Vine^ 
at the proper feafons, young HoneyfuckU 
fhoots, young Afparagus, and young Sun- 
flowers ; and I found in them all a gradual 
icale of unequal extenfions, thofe parts ex- 
tending moll which were tendereft. The 
white part of the Afparagus, which was 
under-ground, extended very little in length, 
and accordingly wc find the fibres of the 
white part very tough and ftringy : But the 
greateft extenfion of the tender green part, 
which was about four inches above the 
ground when I marked it, feparated the marks 
from a quarter of an inch to twelve inches 
diftance ; the greateft diftention of the Sun- 
flower was from ± inch to four inches di- 

From thefe Experiments it is evident, that 
the growth of a young bud to a (hoot con- 
fifts in the gradual dilatation and extenfion 
of every part, the knots of a (hoot being 
very near each other in the bud, as may 
plainly and diftinctly be feen in the flit bud 
of the Vine and Fig-tree -, but by this gra- 
dual diftenfion of every part, they are ex- 
tended to their full length. And we may 
eafily conceive how the longitudinal capil- 
lary tubes ftill retain their hollownefs, not- 


Of. Vegetation. 33^ 

withftanding their being diftended, from the 
like effedt in melted glafs-tubes, which retain 
a hollownefs; tho' drawn out to the fineft 

The whole progrefs of the firft joint r is 
very (hort in comparifon of the other joints, 
becaufe at firft fetting out its leaves being 
very fmall, and the feafon yet cooler than 
afterwards, 'tis probable that but little fap 
is conveyed to it ; and therefore it extending 
but flowly, its fibres are in the mean time 
grown tough and hard, before it can arrive 
to any confiderable length. But as the feafon 
advances, and the leaves inlarge, greater 
plenty of nourifhment being thereby con- 
veyed, the fecond joint grows longer than the 
firft, and the third and fourth ftill on gra- 
dually longer than the preceding; thefe do 
therefore, in equal times, make greater ad- 
vances than the former. 

The wetter the feafon, the longer and 
larger {hoots do Vegetables ufually make ; 
becaufe their foft ductile parts do then con- 
tinue longer in a moift, tender ftate : but in 
a dry feafon the fibres fooner harden, and 
flop the further growth of the (hoot -, and 
this may probably be one reafon why the 
two or three laft joints of every fhoot arc 


3 ? 6 9/" Vegetation. 

ufually fhorter than the middle joints, vivk 
bccaufe they (hooting out in the more ad- 
vanced hot dry fummer ffcafon, their fibres 
are foon hardened and dried, and are withal 
checked in their growth by the cool autum- 
nal nights : I had a Vine-moot of one year's 
growth, which was 14 feet long, and had 39 
joints, all pretty nearly of an equal length, 
except fome of the firft and laft. 

And for the fame reafon, Beans and many 
other plants, which ftand where they are 
much fhaded, being thereby kept continually 
moid, do grow to unufual heights, and are 
drawn up, as they call it, by the over-fhadow- 
ing trees, their parts being kept long, foft 
and dudtile: f But this very moid: fhaded ftate 
is ufually attended with flerility; very long 
joints of Vines are alfo obferved to be un- 

This Experiment, which {hews the man- 
ner of the growth of moots, confirms Borel/i's 
opinion, who, in his Book De motu Ani- 
malium, Part fecond, Chap. 13. fuppcfes 
the tender growing moot to be diftended, 
like fofc wax, by the expaniion of the moi- 
fture in the fpongy pith ; which dilating 
moifturc, he with good reafon concludes, 
is hindered from returning back, (while it 


Of Vegetation. 337 

expands) by the fponginefs of the pith, with- 
out the help of valves. For 'tis very pro- 
bable, that the particles of water, which im- 
mediately adhere to, and are ftrongly im- 
bibed into, and attracted by every fibre of 
the fpongy pith, will fufFer fome degree of 
expanfion, before they can be detach'd by the 
fun's warmth from each attracting fibre ; and 
confequently the mafs of fpongy fibres, of 
which the pith confifts, muft thereby be 

And that the pith may be the more fer- 
viceable for this purpofe, Nature has pro- 
vided, in moft (hoots, a ftrong partition at 
every knot ; which partitions ferve not only 
as plinths or abutments for the dilating pith 
to exert its force on, but alfo to prevent the 
rarefied fap's too free retreat from the pith, 
as well as for the (hooting forth of branches^ 
leaves and fruit. 

But a dilating fpongy fubftance, by equally 
expanding itfelf every way, would not pro- 
duce an oblong fhoot, but rather a globofe 
one, like an Apples to prevent which incon- 
venience we may obferve, that Nature has 
provided feveral Diaphragms, befides thofe 
at each knot, which are placed at fmall di- 
ftances acrofs the pith, thereby preventing 

Z its 

3 } 8 Of Vegetation. 

its too great lateral dilatation. Thefe are very 
plain to be feen in Walnut-tree fhoots : And 
the fame we may obferve in the pith of the 
branches of the Sun-flower, and of feveral 
other plants ; where, tho' thefe Diaphragms 
are not to be diftinguifhed, while the pith is 
full and replete with moifture, yet when it 
dries up, they are often plain to be feen : and 
it is further obferved, that where the pith 
confifts of diftinct veficles, the fibres of thofe 
veficles are often found to run horizontally, 
whereby they can the better refift the too 
great lateral dilatation of the fhoot. 

We may obferve, that Nature makes ufe of 
the fame artifice in the growth of the feathers 
of Birds, which is very vifible in the great pi- 
nion feathers of the wing, the fmaller and 
upper part of which is extended by a fpongy 
pith, but the lower and bigger quill-part by a 
feries of large veficles, which, when replete 
with dilating moifture, do extend the quill, 
and keep it in a fupple ductile flate - y but when 
the quill is full grown, thefe veficles are always 
dry : in which ftate we may plainly obferve 
every veficle to be contracted at each end by 
a Diaphragm or Sphincter, whereby its too 
great lateral dilatation is prevented, but not 
its diftenfion lengthwife. 


Of Vegetation. 3 3 9 

And as this pith in the quill grows dry and 
ufelefs after the quill is full-grown, v/e may 
obferve the Fame in the pith of trees, which 
is always fucculent, and full of moifture, while 
the fhoot is growing, by the expanfion of 
which the tender ductile fhoot is diftended in 
every part, its fibres being at the fame time 
kepi fupple by this moifture ; but when each 
year's moot is full grown, then the pith gra- 
dually dries up, and continues for the future 
dry and kecfey, its veficles being ever after 
empty, Nature always carefully providing for 
the fucceeding year's growth, by preferving 
a tender ductile part in the bud replete with 
fucculent pith. 

And as in Vegetables, fo doub clefs in Ani- 
mals, the tender ductile bones of young Ani- 
mals are gradually increafed in every part, 
that is not hardened and offiried $ but fince it 
was inconfiflent with the motion of the joints 
to have the ends of the bones foft and ductile, 
as in Vegetables, therefore Nature makes a 
wonderful provifion for this at the glutinous 
ferrated joining of the heads to the flianks of 
the bones ; which joining, while it continues 
ductile, the Animal grows ; but when it offifie&v 
then the Animal can no longer grow: As I 
was affured by the following Experiment, viz* 

Z 2, I 

340 Of Vegetation. 

I took a half-grown Chick, whole leg-bone 
was then two inches long j and with a fharp- 
pointediron, at half an inch diftance, I pierced 
two fmall holes thro' the middle of the fcaly 
covering of the leg and fhin-bone ; two months 
after I killed the Chick, and upon laying the 
bone bare, I found on it obfcure remains of 
the two marks I had made at the fame diftance 
of half an inch : So that that part of the bone 
had not at all diftended lengthwife, fince the 
time that I marked it} notwithstanding the 
bone was in that time grown an inch more 
in length, which growth was moftly at the 
upper end of the bone, where a wonderful 
provifion is made for its growth at the join- 
ing of its head to the fhank, called by Anato- 
mifts hymphyfis. 

And as the bones grow in length and fize, 
fo mud the membranous, the mufcular, the 
nervous, the cartilaginous and vafcular fibres 
of the animal body neceffarily extend and ex- 
pand, from the duftile nutriment which Na- 
ture furnifhes every part withal ; in which 
refpe&s animal bodies do as truly vegetate as 
do the growing Vegetables : Whence it mud 
needs be of the greateft confequcnce, that the 
growing Animal be fupplied with proper nou- 
rishment for that purpofe, in order to form a 


Of Vegetation. 341 

ftrong athletick conflitution ; for when grow- 
ing Nature is deprived of proper materials for 
this purpofe, then is me under a neceffity of 
drawing out very {lender threads of life, as is 
too often the cafe of young growing perfons 3 
who, by indulging in fpirituous liquors, or 
other exceffes, do thereby greatly deprave the 
nutritive duftile matter, whence all the dif- 
tending fibres of the body are fupplied. 

Since we are by thefe Experiments allured, 
that the longitudinal fibres and fap-veffels of 
wood in its firft year's growth, do thus diftend 
in length by the extenfion of every part; and 
fince Nature in limilar produftions makes ufe 
of the fame, or nearly the fame methods, thefe 
confiderations make it not unreafonable to 
think, that the fecond and following years 
additional ringlets of wood are not formed 
by a merely horizontal dilatation of the vef- 
fels; for it is not eafy to conceive, how lon- 
gitudinal fibres and tubular fap-veffels fhould 
thus be formed, but rather by the mooting 
of the longitudinal tubes and fibres length- 
ways from thofe of the laft year's wood, 
whereby there is a free communication main- 
tained between thefe and the fap-veffels of all 
the preceding year's growth. The obferva- 
tions on the manner of the growth of the 
Z 3 ringlets 

34* Of Vegetation. 

ringlets of wood in Experiment 46. (Fig. 30.) 

do further confirm this. 

But whether it be bv an horizontal or Ion- 
gitudinal (hooting, we may obferve that Na- 
ture has taken great care to keep the parts 
between the bark and wood always very fup- 
ple with flimy moifture ; from which ductile 
matter the woody fibres, veficles and buds are 

Thus wc fee that Nature, in order to the 
production and growth of all the parts of 
Animals and Vegetables, prepares her du&ile 
matter ; in doing of which (he felects and 
combines particles of very different degrees 
of mutual attraction, curioufly proportioning 
the mixture according to the many different 
purpofes (he defigns it for ; either for bony or 
more lax fibres of very different degrees in 
Animals, or whether it be for the forming 
of woody or more foft fibres of various kinds 
in Vegetables, 

The great variety of which different fub- 
ftances in the fame Vegetable prove, that 
there are appropriated veffels for conveying 
very different forts of nutriment. And in 
many Vegetables fome of thofe appropriate 
veffels are plainly to be ktn replete either 
with milky, yellow, or red nutriment. 


Of Vegetation. 34$ 

Dr. KtilL in his account of animal fecre- 
tion, page 49. obferves, that where Nature 
intends to feparate a vifcid matter from the 
blood, fhe contrives very much to retard its 
motion^ whereby the inteftine motion pf the 
blood being allayed, its particles can the bet- 
ter coalefce, in order to form the vifcid fecre- 
tion. And Dr. Grew, before him, obferved 
an inftance of the fame contrivance in Vege- 
tables, where a fecretion is intended, that is 
to compofe a hard fubftance, viz. in the ker- 
nel or feed of hard (tone fruits, which does 
not immediately adhere to, and grow from 
the upper part of the ftone, which would be 
the {horteft and neareft way to convey nou- 
rifhment to it ; but the fingle umbilical vef- 
fel, by which the kernel is nourished, fetches 
a compafs round the concave of the ftone, 
and then enters the kernel near its cone; by 
which artifice this veffel being much pro- 
longed, the motion of the fap is thereby re- 
tarded, and a vifcid nutriment conveyed to 
the feed, which turns to hard fubftance. 

The like artifice of Nature we may obferve 
in the long capillary fibrous veflels, which lie 
between the green hull and the hard fhell of 
the Walnut, which are analogous to the 
fibrous Mace of Nutmegs, the ends of whofe 
Z 4 hairy 

3 44 Of Vegetation. 

hairy fibres are inferted into the angles of the 
furrows in the Walnut-fhell : Their ufe is 
therefore doubtlefs to carry in thofe long di- 
ftincl veffels the very vifcous matter, which 
turns, when dry, to a hard (hell \ whereas, 
were the fhell immediately nourished from 
the foft pulpous hull that furrounds it, it 
would certainly be of the fame foft conftitu- 
tion, the ufe of the hull being only to keep 
the lhcl! in a foft ductile ftate, till the Nut has 
done growing. 

We may obferve the like effect of a flower 
motion of the fap in Ever-greens, which per- 
fpiring little, their fap moves much more 
flowly than in more perfpiring trees, and is 
therefore much more vifcid, whereby they 
are better enabled to out-live the winter's 
cold. It is obferved, that the fap of Ever- 
greens in hot countries is not fo vifcous as the 
fap of more northern Ever-greens, as the Fir, 
&c. for the fap in hotter countries mud have 
a brisker motion, by means of its greater per- 

Experiment CXXIV. 

In order to inquire into the manner of the 
expanfion of leaves, I provided a little oaken 
board or fpatula, a b c d> of this fhape and 


Of Vegetation. 34 j 

fize (Fig. 43.) ; through the broad part, at a 
quarter of an inch diftance from each other, 
I run the points of 25 pins x x, which flood 
\ inch thro', and divided a fquare inch into 
16 equal parts. 

With this inftrument in the proper feafon, 
when leaves were very young, I pricked feve- 
ral of them thro' at once with the points of 
all thefe pins, dipping them firft in the red T 
lead, which made lafting marks. 

(Fig. 44.) reprefents the fhape and fize of 
a young Fig-leaf, when firft marked with red 
points, i. inch diftance from each other. 

(Fig. 45.) reprefents the fame full-grown 
leaf, and the numbers anfwer to the corre- 
fponding numbers in the young leaf; whereby 
may be feen how the feveral points of the 
growing leaf were feparated from each other, 
and in what proportion, viz. from a quarter 
of an inch to about three quarters of an inch 

In this Experiment we may obferve, that 
the growth and expanfion of the leaves is 
owing to the dilatation of the veficles in every 
part, as the growth of a young fhoot was 
fhewn to be owing to the fame caufe in the 
foregoing Experiment, and doubtlefs the cafe 
is the fame in all fruits. 


34*> Of Vegetation. 

If thefe Experiments on leaves were further 
purfued, there might probably be many curi- 
ous obfervations made in relation to the fhape 
of leaves, by obferving the difference of the 
progreflive and lateral motions of thefe points 
in different leaves, that were of very different 
lengths in proportion to their breadths. 

That the force of dilating fap and air, in- 
cluded in the innumerable little veficles of 
young tender fhoots and leaves, is abundantly 
iufficient for the excending of fhoots, and ex- 
panding of leaves; we have evident proof 
from the great force we find in the fap of the 
Vine, chap. 3. and from the vaft force with 
which infinuating moifture expanded the 
Peas. Experiment 3 2. we fee the great power 
of expanding water, when heated in the 
engine to raife water by fire j and water with 
air and other active particles in capillary tubes, 
and innumerable fmall veficles, do doubtlefs 
act with a great force, tho' expanded with 
no more heat than what the fun's warmth 
gives them. 

And thus we fee that Nature exerts a con- 
fiderable, tho' fecret and filenc power, in car- 
rying on all her productions; which demon- 
strates the wifdom of the Author of nature, 
in giving fuch due proportion and direction 


PL- 13 

[] P!34$ 


1 J J J J J 

J J J J -J 

j x J J X J J 

j y y y y 

j j -j j j 




34^ 0/ Vegetation. 

a very confiderable influence in expanding 
the fap in all its parts. The warmth was 
much greater on the body above-ground, than 
on the roots which were two feet deep ; thofe 
roots, and parts of roots, which are deeped, 
as they feel much lefs of the fun's warmth, 
fo are they not fo foon, n j; fo much affected 
by the alternacies of day and night, warm 
and cold : but that part of Vegetables which 
is above-ground, mull have its fap consider- 
ably rarefied, when the heat increafed from 
morning to two o'clock afternoon, fo much 
as to raife the fpirit in the ift Thermometer 
from 21 to 48 degrees above the freezing 

When in the coldeft days of the winter 
1724, the froft was fo intenfc as to freeze the 
furface of ftagnant water near an inch thick, 
then the fpirit in the Thermometer y which was 
expofed to the open air, was fallen four de- 
grees below the freezing point; the fpirit of 
that whofe ball was two inches under-ground, 
was four degrees above the freezing point; 
the 3d, 4th and 5th Thermometers were pro- 
porlionably fallen lefs and lefs, as they were 
deeper, to the 6th Thermometer ; which being 
two feet under-ground, the fpirit was ten 
degrees above the freezing point. In this 


Of Vegetation. 349 

ftate of things the work of Vegetation feemed 
to be wholly at a (land, at lead within the 
reach of the froft. 

But when the cold was fo far relaxed, as 
to have the fpirit in the firft Thermometer 
but five degrees above the freezing point, the 
fecond 8 degrees, and the fixth 13 degrees, 
tho' it was flill very cold, yet this being fome 
advance from freezing towards warm, and 
there being confequently fome expanfion of 
the fap, feveral of the hardy Vegetables grew, 
viz. fome Ever-greens, Snow-drops, Crocus's, 
&c. which forward hardy plants do proba- 
bly partake much of the nature of Ever- 
greens in perfpiring little ; and the motion 
of their fap being confequently very flow, it 
will become more vifcous, as in Ever-greens, 
and thereby the better able to refift the win- 
ter's cold ; and the fmall expanfive force 
which this fap acquires in the winter, is 
moftly exerted in extending the plant, little 
of it being wafted in proportion to the fum- 
mer's perfpiration. 

Supported by the evidence of many of the 
foregoing Experiments, I will now trace the 
Vegetation of a Tree from its firft feminal 
plant in the Seed to its full maturity and pro- 
duction of other Seeds, without cntring into 

a par- 

l$o Of Vegetation. 

a particular defcripiion of the ftrudlure of the 
parts of Vegetables, which has already been 
accurately done by Dr. Grew and Malpighi. 

We fee by Experiment 56. 57. 58. on di- 
ftilled Wheat, Peas, and Muftard-feed, what 
a wonderful provifion Nature has made, thac 
the Seeds of Plants fhould be well ftored with 
very active principles, which principles are 
there compacted together by Him, who curi- 
oufly adapts all things to the purpofes for 
which they are intended, with fuch a juft 
degree of cohefion, as retains them in that 
ftate till the proper feafon of germination : 
for if they were of a more lax conftitution, 
they would too foon diffolve, like the other 
tender annual parts of plants ; and if they 
were more firmly connected, as in the heart 
of Oak, they muft neceflarily have been many 
years in germinating, though fuppled with 
moifture and warmth. 

When a Seed is fown in the ground, in 
a few days it imbibes lb much moifture, as 
to fwell with very great force ; as we fee in 
the Experiment on Peas in an iron pot, 
this forcible fwelling of the lobes of the 
Seed a r, a r, (Fig. 46.) does probably pro- 
trude moifture and nourifhment from the 
capillary veffels r r, which are called the 


Of Vegetation. 3 5 1 

Seed-roots, into the radicle c z d; which 
radicle, when it has fhot fome length into 
the ground, does then imbibe nourifhmcnt 
from thence ; and after it has acquired fuf- 
ficient ftrength, as this tender ductile root 
is extending from z to c, it muft necefla- 
rily carry the expanding Seed-lobes upwards, 
at the fame time that the dilating from z to 
d makes it fhoot downwards ; and when 
the root is thus far grown, it fupplies the 
Plume b with nourifhment, which thereby 
fvvelling and extending, opens the lobes a r r 
a r, which are at the fame time raifed 
above ground with the Plume; where they, 
by expanding and growing thinner, turn to 
green leaves (except the Seeds of the Pulfe 
kind); which leaves are of fuch importance 
to the yet tender Plume, that it perifhes, or 
will not thrive if they are pulled off; which 
makes it probable, that they do the fame 
office to the Plume, that the leaves adjoining 
to Apples, Quinces, and other fruits, do to 
them, viz, they draw fap within the reach 
of their attraction; fee Exper. 8. and 30. 
But when the Plume is fo far advanced in 
growth, as to have branches and expanded 
leaves to draw up nourifhment ; then thefe 
fupplemental feminal leaves, a r, a r, being of 


3 5 l Of Vegetation. 

n^ farther ufe, do perifti; not only bccaufe 
the now grown and more expanded leaves 
of the young plant or tree do fo over-fhadow 
the fupplemental leaves, that their former 
more plentiful perfpiration is much abated, 
and thereby alfo their power of attracting fap 
fails ; but alfo, becaufe the fap is drawn from 
them by the leaves, and they being thus de- 
prived of nourifhment, do perifh. 

As the tree advances in ftature, the firft, 
fecond, third, and fourth order of lateral 
branches (hoot out, each lower order being 
longer than thofe immediately above them -, 
not only on account of primogeniture, but 
alfo, becaufe being inferted in larger parts of 
the trunk, and nearer the root, they have the 
advantage of being ferved with greater plenty 
of fap, whence arifes the beautiful parabo- 
lical figure of trees. 

But when trees ftand thick together in 
Woods or Groves, this their natural fhape is 
altered, becaufe the lower lateral branches 
faeing much fhaded, they can perfpire little ; 
and therefore drawing little nourishment, 
they perifh ; but the top branches being ex- 
pofed to a free drying air, they perfpire plen- 
tifully, and thereby drawing the fap to the 
top, they advance much in height : But vice 


Of Vegetation. 353 

versa, if, when fuch a Grove of tall trees is 
cut down, there be left here and there a fingle 
tree, that tree will then (hoot out lateral 
branches $ the leaves of which branches now 
perfpiring freely, will attradt plenty of fap, 
on which account the top being deprived of 
its nourifhment, it ufually dies. 

And as trees in a Grove or Wood grow 
only in length, becaufe all the nourifhment 
is by the leaves drawn to the top, moft of 
the fmall lateral (haded branches in the mean 
time perifhing for want of perfpiration and 
nutrition 5 fo the cafe is the very fame in the 
branches of a tree, which ufually making an 
angle of about 45 degrees with the ftem of 
the tree, do thereby beautifully fill up, at equal 
and proper diftances, the fpace between the 
lower branches and the top of the tree, form- 
ing thereby, as it were, a parabolical Grove or 
Thicket, which (hading the arms, the fmall 
lateral (hoots of thofe arms ufually perifti for 
want of due perfpiration ; and therefore the 
arms continue naked like the bodies of trees 
in a grove, all the nourifhment being drawn 
up to the tops of the feveral branches by the 
leaves which are there expofed to the warm 
fun } and free drying air, whereby the branches 
of trees expand much. 

A a And 

3 54 Of Vegetation. 

And where ihe lateral branches are very 
vigorous, fo as to make ftrong (hoots, and 
attract the nourimment plentifully, there the 
tree ufually abates in its height : But where 
the tree prevails in height, as in groves, there 
commonly its lateral branches are (mailed. 
So that we may look upon a tree as a com- 
plicated Engine, which has as many different 
powers as it has arms and branches, each 
drawing from their common fountain of life 
the root : and the whole of each yearly growth 
of the tree will be proportionable to the fum 
of their attracting powers, and the quantity 
of nourifliment the root affords : But this at- 
tracting power and nourishment will be more 
or lefs, according to the different ages of the 
tree, and the more or lefs kindly feafons of 
the year. 

And the proportional growth of their late- 
ral and top branches, in relation to each other, 
will much depend on the difference of their 
feveral attracting powers. If the perforation 
and attraction of the. lateral brances is little 
or nothing, as in woods and groves, then the 
top branches will mightily prevail -, but when 
in a free open air the perfpiration and attra- 
ction cf the lateral branches comes nearer to 
an equality with that of the top, then are the 


Of Vegetation. * 355 

aiplrings of the top branches greatly checked. 
And the cafe is the fame in moft other Vege- 
tables, which, when they ftand thick toge- 
ther, grow much in length with very weak 
lateral (hoots. 

And as the leaves are thus ferviceable in 
promoting the growth of a tree, we may ob- 
ferve that Nature has placed the petals of the 
lea ves-ftalks where moft nourimment is want- 
ing, to produce leaves, {hoots and fruit ; and 
fome fuch thin leafy expanfion is fo neceflary 
for this purpofe, that Nature provides fmall 
thin expanfions, which may be called pri- 
mary leaves, that ferve to protect and draw 
nourishment to the young (hoot and leaf-buds, 
before the leaf itfelf is expanded. 

And herein we fee the admirable contri- 
vance of the Author of nature in adapting 
her different ways of conveying nourishment 
to the different circumftances of her produ- 
ctions. For in this embryo ftate of the buds 
a fuitable provifion is made to bring nourish- 
ment to them in a quantity fufficient for their 
then fmall demands : But when they are in 
fome degree increafed and formed, a much 
greater quantity of nourimment is neceflary, 
in proportion to their greater increafe : Na- 
ture, that fhe may then no longer fupply with 
A a 2 a 

35<* Of Vegetation. 

a fcanty hand, immediately changes her me- 
thod, in order to convey nourishment with 
a more liberal hand to her productions; 
which fupply daily increafes by the greater 
expanfion of the leaves, and confequently the 
more plentiful attra&ion and fupply of fap, 
as the greater growth and demand for it in- 

We find a much more elaborate and beau- 
tiful apparatus, for the like purpofe, in the 
curious expanfions of blofToms and flowers, 
which feem to be appointed by Nature not 
only to protedl, but alfo to draw and convey 
nourishment to the embryo fruit and feeds. 
But as foon as the Calix is formed into a 
fmall fruit, now impregnated with its minute 
feminal tree, furnifhed with its Secondine, 
Corion and Amnion, (which new-fet fruit 
may, in that ftate, be looked upon as a com- 
plete egg of the tree, containing its young 
unhatched tree, yet in embryo) then the blof- 
fom falls off, leaving this new-formed egg, 
or firft-fet fruit, in this infant ftate, to im- 
bibe nourifhment fufficient for itfelf, and the 
Fcetus with which it is impregnated : Which 
nourifhment is brought within the reach 
and power of its futtion by the adjoining 


Of Vegetation. 357 

If I may be allowed to indulge conjecture 
in a cafe in which the mod diligent inquirers 
are as yet, after all their laudable refearches, 
advanced but little farther than mere con- 
jecture, I would propofe it to their confidera- 
tion, whether from the manifeft proof we 
have that fulphur ftrongly attrafts air, a hint 
may not be taken, to confider whether this 
may not be the primary ufe of the Farina 
fcecundans, to attradt and unite with itfelf 
elaftick or other refined adtive particles. That 
this Farina abounds with fulphur, and that 
a very refined fort, is probable, from the 
fubtle oil which Chymifts obtain from Saf- 
fron. And if this be the ufe of it, was it 
poflible that it could be more aptly placed 
for the purpofe, than on very moveable apices 
fix t on the flender points of the Stamina, 
whereby it might eafily, with the lead breath 
of wind, be difperfed in the air, thereby fur- 
rqunding the plant, as it were, with an At- 
mofphere of fublimed fulphureous pounce ? 
(for many trees and plants abound with it) 
which uniting with the air-particles, they, 
or a very fublimed fpirit from them, may, 
perhaps, be infpired or imbibed at feveral 
parts of the plant, and efpecially at the Piftil- 
lum 7 and be thence conveyed to the Capjula 
A a 3 femi~ 

358 Tlie Conclvjion. 

feminalis, efpecially towards evening, and in 
the night, when the beautiful Petala of the 
flowers are clofed up, and they, with all the 
other parts of the Vegetable, are in a ftrongly 
imbibing flat-'. And if to thefe united ful- 
phureous and aereal particles, we fuppofe 
fome particles of light to be joined, (for Sir 
Ijaac Ne<wton has found, that fulphur attracts 
light ftrongly) then the refult of thefe three, 
by far the moll: active principles in Nature, 
will be a Punftum Saliens, to invigorate the 
Jeminal plant : And thus we are at laft con- 
ducted, by the regular Analyfis of vegetable 
Nature, to the firft enlivening principle of 
their minuteft Origin. 

The Conchjion. 

WE have, from the foregoing Experi- 
ments, many proofs of the very great 
and different quantities of moifture imbibed 
and peripired by different kinds of Trees, 
and alfo of the influence the feveral ftates of 
the air, as to warm or cold, wet or dry, have 
on that perfpiration. We fee alio what ftores 
of moifture Nature has provided in the Earth 
againft a dry feafon, to anfwer this great ex- 
pence of it in the production and fupport of 
Vegetables 3 hpw far the Dew can contribute 


The Conchjkn. 359 

to this fupply, and how inefficient its fmall 
quantity is towards making good the great 
demands of perfpiration : And that plants can 
plentifully imbibe moifture thro' their Items 
and leaves, as well as perfpire it. 

We fee with what degrees of warmth the 
Sun, that kindly natural genius of Vegetation, 
ads on the feveral parts of Vegetables, from 
their tops down to their roots two feet under 

We have alfo many proofs of the great 
force with which plants, and their feveral 
branches and leaves, imbibe moifture up their 
capillary fap-veffels : The great influence the 
perfpiring leaves have in this work, and the 
care Nature has taken to place them in fuch 
order, and at fuch proper distances, as may 
render them moft ferviceable to this purpofe, 
efpecially in bringing plenty of nouridiment 
to the young growing fhoots and fruit, whofe 
item is ufually furrounded with them near 
the fruit's infertion into the twig. 

We fee here too, that the growth of fhoots, 
leaves and fruit, confifts in the cxtenfion of 
every part ; for the effecting of which, Nature 
has provided innumerable little veiicles, which 
being replete with dilating moifture, it does 
thereby powerfully extend, and draw out every 
dudile parr. A a 4 We 

3^o The Conchfion. 

We have here alfo many inftances of the 
great force of the afcending fap in the Vine in 
the bleeding feafon; as alfo of the fap's freely 
either afcending or defcending, as it fhall hap- 
pen to be drawn by the perfpiring leaves ; and 
alfo of its ready lateral motion thro' the late- 
rally communicating fap-veffels ; together 
with many proofs of the great plenty of air 
drawn in and mixt with the fap, and incor- 
porated into the fubftance of Vegetables. 

If therefore thefe Experiments and Obfer- 
vations give us any farther infight into the 
nature of plants, they will then doubtlefs be 
of fome ufe in Agriculture and Gardening, 
either by ferving to re&ify fome miftaken. 
notions, or by helping farther to explain the 
reafons of many kinds of culture, which long 
repeated experience has found to be good, and 
perhaps by leading us to make fome advances 
therein : But as it requires a long feries and 
great variety of frequently repeated Experi- 
ments and Obfervations to make a very fmall 
advance in the knowledge of the nature of 
Vegetables, fo proportionably we are from 
thence only to exped: fome gradual improve- 
ments in the culture of them. 

The fpecifick differences of Vegetables, 
which are all fuftained and grow from the 


The Conclufion. $61 

fame nourishment, is doubtlefs owing to the 
very different formation of their minute vef- 
fels, whereby an almoft infinite variety of 
combinations of the common principles of 
Vegetables is made $ whence fome abound 
more with fome principles, and fome with 
others. Hence fome are of a warmer and 
more fulphureous, others of a more watry, 
faline, and therefore colder nature; fome of a 
more firm and lading, others of a more lax 
and perifhable conftitution. Hence alfo it is 
that fome plants flourish beft in one climate, 
and others in another ; that much moifture is 
kindly to fome, and hurtful to others; that 
fome require a ftrong, rich, and others a poor, 
fandy foil ; fome do beft in the {hade, and 
others in the fun, &c. And could our eyes 
attain to a fight of the admirable texture of 
the parts on which the fpecifick differences in 
plants depend, what an amazing and beautiful 
fcene of inimitable embroidery fhould we be- 
hold ? what a variety of mafterly ftrokes of 
machinery ? what evident marks of confum- 
mate wifdom fhould we be entertained with? 

We may obferve, that the conftitution of 
plants is curioufly adapted to the prefent ftate 
of things, fo as to be moft flourifhing and 
vigorous in a middle ftate of the air, viz. 


3 6 2 The Conchjion. 

when there is a due mixture and proportion 
of warm and cold, wet and dry ; but when 
thefeafons deviate far to any extreme of thefe, 
then are they lefs or more injurious to the 
feveral forts of Vegetables, according to the 
very different degrees of hardinefs, or healthy 
latitude they enjoy. 

The different feafons in which plants thrive 
beft, feem to depend, among other caufes, on 
the very different quantities imbibed and per- 
fpired by different kinds of plants. Thus 
the Ever-greens perfpiring little, and having 
thereby a thick, vifcid, oily fap, they can the 
better endure the winter's cold, and fubfift 
with little frefh nourishment : They feem 
many of them to flourish moft in the tem- 
perate feafons of the year, but not fo well in 
the hotteft part of fummer, becaufe their per- 
fpiration is then fomewhat too great, in pro- 
portion to the flow afcent of the fap, which 
makes fome of them at that feafon to abate of 
their vigour : Thus fome plants, which grow 
and thrive with the flow perfpiration of Ja- 
nuary and February , perifh as the fpring ad- 
vances, and the warmth and perfpiration is 
too great for them. And thus Garden Peas 
and Beans, which are fown in what is found 
to be their proper feafon, viz. in November, 


The Conchjion. 363 

January, or February, tho' they make but a 
ilow progrefs in their growth upwards, du^ 
ring the cold feafon, yet their roots, as alfo 
thofe of winter Corn, do in the mean time 
fhoot well into the warmer earth, fo as to be 
able to afford plenty of nourishment when 
the feafon advances, and there is a greater 
demand of it both for nutrition and perfpira- 
tion. But when Peas are fown in June, in 
order for a crop in September,- they rarely 
thrive well, unlefs in a cool moift fummer, 
by reafon of the too great perfpiration caufed 
by the fummer's heat, which dries and har- 
dens their fibres before they are full grown. 

Tho* we have from thefe Experiments, 
and from common obfervation, many proofs 
of the great expanfive force, with which the 
fibrous roots of plants moot, yet the lefs re- 
finance thefe tender fhoots meet with, the 
greater progrefs they will certainly make in 
equal times : And therefore one confiderable 
ufe of fallowing and trenching ground, and 
of mixing therewith feveral forts of compoft, 
as Chalk, Lime, Marie, Mould, &c. is not 
only thereby to replenifh it with rich manure, 
but alfo to loofen and mellow the foil, not 
only that the air may the more eafily pene- 
trate to the roots, but alfo that the roots may 


364 7#£ Conch fion. 

the more readily make vigorous flioots. And 
the greater proportion the furface of the roots 
bears to the furface of the plants above- 
ground, fo much the greater quantity of 
nourifhment they will afford; and confe- 
quently the plants will be the more vigorous, 
and better able to weather it out, againft 
unkindly feafons, than thofe plants whofe 
roots have made much (horter flioots. Herein 
therefore confifts the great care and skill of 
the Husbandman, to adapt his different forts 
of Husbandry to the very different foils, feafons 
and kinds of grain ; that the feveral forts of 
earth, from the very ftiff and ftrong ground, 
to the loofe light earths, may be wrought to 
the beft temper they are capable of, for the 
kindly fhooting and nourifliing of the roots. 
And probably the Husbandman might get 
many ufeful hints, to dired: him in adapt- 
ing the feveral kinds of manure, and dif- 
ferent forts and feafons of culture, to his 
different foils and grains, if in the feveral 
flages and growth of his Corn he would 
not only make his obfervations on what 
appears above-ground, but would alfo fre- 
quently dig up, compare and examine the 
roots of plants of each fort, efpecially cf 
thofe which grew in different foils, and were 


The Conclufion. 365 

any how cultivated in a different manner from 
each other; this would inform them alfo, 
whether they fowed their Corn too thick or 
too thin, by comparing the branchings and 
extent of each root, with the fpace of ground 
allotted it to grow in. 

And fince we find fo great a quantity of 
air infpired and mixt with the fap, and 
wrought into the fubftance of Vegetables, 
the advantage of ploughing and fallowing 
ground feems to arife not only from the 
killing the weeds, and making it more mel- 
low, for the (hooting of the roots of Corn 3 
but it is thereby alfo the better expofed to 
have the fertilizing, fulphureous, aereal, and 
acid particles of the air mixt with it, which 
make land fruitful, as is evident from the 
fertility which the fword or furface of land 
acquires, by being long expofed to the air, 
without any culture or manure whatever. 

We have feen many proofs of the great 
quantities of liquor imbibed and perfpired 
by plants, and the very fenfible influence 
which different ftates of the air had on their 
more or lefs free perfpiration : A main in- 
tention therefore to be attended to in the 
culture of them, is to take due care, that 
they be fown or planted in proper feafons 


$66 The Conchjion. 

and foils, fuch as will afford them their due 
proportion of nourifhment ; which foils, as 
they are exhaufted, muft, as 'tis well known, 
from time to time, be replenifhed with frefh 
compoft, fuch as is full of faline, fulphu- 
reous and aereal particles, with which com- 
mon dung, lime, afhes, fword, or burn- 
bated turf abound ; as alfo fuch manures, 
as have nitrous and other falts in them : for 
tho' neither nitre nor common fait be found 
in Vegetables, yet fince they are obfcrved to 
promote fertility, it is reafonable to con- 
clude, that their texture is greatly altered 
in Vegetation, by having their acid volatile 
falts feparated from the attracting central 
air and earthy particles, and thereby make- 
ing new combinations with the nutritive 
juice ; and the probability of this is further 
confirmed, from the great plenty of air and 
volatile fait, which is found in another com- 
bination of them, viz. in the Tartar of 
fermenting liquors : For it is the opinion of 
Chymifts, that there is but one volatile Salt 
in nature, out of which all other kinds of 
falts are formed by very different combina- 
tions; all which nutritive principles do, by 
various combinations of the cultivated earth, 
compofe that nutritive dudtile matter, out 


tfhe Conchjiori. ^67 

of which the parts of Vegetables are formed, 
and without which the watry vehicle alone 
cannot render a barren foil fruitful. 

Nor is this the only care : The thriving 
and fertility of plants and trees depends 
much upon the happy influence and con- 
currence of a great variety of other cir- 
cumftances. Thus many trees are unfruit- 
ful by being planted too deep, whereby 
their roots being in too moift a ftate, and 
too far from the proper influence of the 
Sun, whofe power greatly decreafes, the 
deeper we go, as we fee in Experiment 20. 
they imbibe too much crude moifture, which, 
tho' productive of wood, is yet unkindly for 

Or if, when not planted too deep, they 
are full of crude fap, either by being too 
luxurious, or too much fhaded ; or are 
planted in a moift, when they delighc in a 
dry foil, then the fap is not fo fufficiently 
digefted by the Sun's warmth, as to be in 
that dudtile ftate, which is proper for the 
producing of fruit. 

And thus the Vine, which is known to 
thrive w 7 ell in a dry, gravelly, rocky foil, 
will not be fo fruitful in a moift, ftifF, clay 
ground: And accordingly we -may obferve 


3 68 The Conchjion. 

in Experiment 3. that tho' the Vine imbibed 
and perfpired more than the Ever-green, yet 
it perfpired lefs than the Apple-tree, which 
delights in, and bears beft in a ftrong brick- 
earth clay ; for tho' the Vine bleeds moil 
freely in its feafon, produces many long 
fucculent fhoots, and bears great plenty of 
a very juicy fruit, yet from that Experiment 
it is plain, that it is not a great perfpirer, 
and therefore thrives beft in a dry, rocky, or 
gravelly foil. 

The considerable quantity of moifture, 
which by Experiment 16. is perfpired from 
the branches of trees, during the cold winter 
feafon, plainly (hews the reafon why, in a 
long feries of cold North-eafterly winds, the 
bloffoms, and tender young-fet fruit and 
leaves, are in the early fpring fo frequently 
blafted, viz. by having the moifture exhaled 
fafter than it can be fupplied from the trees : 
for doubtlefs that moifture rifes the flower 
from the root, the colder the feafon is, tho' it 
rifes in fome degree all the winter^ as is evi- 
dent from the fame Experiment. 

And from the fame caufe it is, that the 
leafy fpires of Corn are, by thefe cold dry- 
ing winds, often faded and turned yellow ; 
which makes the Husbandman, on thefe oc- 


The Conclujion* ^6$ 

tafions, wifh for fnow ; which, tho* it be very 
cold, yet it not only defends the root from 
being frozen, but alfo fcreens the Corn from 
thefe drying winds, and keeps it in a moid, 
florid, fupple ftate. 

It feems therefore to be a very reafonable 
direction, which is given by fome of the 
Authors, who write on Agriculture and Gar- 
dening, viz % during thefe cold drying winds, 
when little dew falls, to water the trees in 
dry foils, in the blofibming feafon, and while 
the young- fet fruit is tender; and provided 
there is no immediate danger of a froft, or in 
cafe of continued froft, to take care to cover 
the trees well, and at the fame time to fprinkle 
them with water, which is imitating Nature's 
method of watering every part : But if the 
fuccefs of this practice in cold weather may 
be thought a little doubtful, yet the fprin- 
kling the bodies and leaves of trees, in a very 
hot and dry fummer feafon, feems mofl rea- 
fonable 5 for by Exper. 42. they will imbibe 
much moifture. 

As to floping fhelters over Wall-trees, I 
have often found, that when they are fo broad 
as to prevent any rain or dew coming at the 
trees, they do more harm than good, in thefe 
long eafterly drying winds, becaufe they pre- 
B b vent 

370 The Conclufion. 

vent the rain and dews falling on them, which 
would not only refrefh and fupple them, but 
alfo convey nourifhment to them : But in the 
cafe of (harp frofts after fhowers of rain, thefe 
fhelters, and other fences, mull needs be of 
excellent ufe to prevent the almoft total de- 
ftrudtion which is occafioned by the freezing 
of the tender parts of Vegetables, when they 
are full faturate with rain. 

The full proof we have from thefe Expe- 
riments, of the ferviceablenefs of the leaves in 
drawing up the hip, and the care we fee Na- 
ture takes in furnifhing the twigs with plenty 
of them, principally near the fruit, may in- 
ftrudt us on the one hand, not to be too lavifh 
in pruning them off*, and to be ever mindful 
to leave fome on the branch beyond the fruit} 
and on the other hand, to be as careful to 
cut oft all fuperflubus fhoots, which we are 
allured to draw off in wafte great quantity of 
nourifliment. And might it not be advife- 
able, among many other ways which are 
prefcribed, to try whether the too great luxu- 
riancy of a tree or branch could not be much 
checked by pulling off fome of its leaves ? 
How many, Experience will beft teach us > 
the pulling all off, will endanger the killing 
the branch or tree. 


The ConcJufion. 371 

There is another very confiderable ufe of 
the leaves, viz. to keep the growing fruit in 
a fupple du&ile ftate, by defending it from 
the fun and drying winds, which by tough- 
ning and hardening its fibres fpoils its growth, 
when too much expofed to them ; but when 
full grown, or near it, a little more fun is 
often very needful to ripen it. In hotter 
climates fruits want more {hade than in this 
country; and here too more fhade is needful 
in a hot dry fummer, than in a wet cool one. 

The confideration of the ftrong imbibing 
power of the branches of trees, and the rea- 
dinefs with which we fee the fap pafles to and 
fro to follow the ftrongeft attraction, may per- 
haps give forne ufeful hints to the Gardener, 
in the pruning and fhaping of his trees, in 
checking the too luxuriant, and helping and 
encouraging the unthriving parts of trees. 

It is a conftant rule among Gardeners, 
founded on long experience, to /prune weak 
trees early in the winter, becaufe they find 
that late pruning checks them 5 and for the 
fame reafbn to prune luxuriant trees late in 
the fpring, in order to check their luxuriancy. 
Now it is evident, that this check does not 
proceed from any confiderable loft of fap at 
l he wounds of the pruned tree, (excepting 

B b 2 che 

%yi The Cbnchfion. 

the cafe of a few bleeding trees when cut in 
that feafon, but muft arife from fome other 
caufe ; for by Experiment 12. and 37. where 
mercurial gages were fixt to the ftems of frefh- 
cut trees, thofe wounds were conftantly in a 
ftrongly imbibing flate, except the Vine in 
the bleeding feafon. 

When a weak tree is pruned early in the 
beginning of the winter, the orifices of the 
fap-veffels are clofed up long before the fpring^ 
as is evident from many Experiments in the 
1 ft, 2d, and 3d chapters : and confequently, 
when in the fpring and fummer the warm 
weather advances, the attracting force of the 
perfpiring leaves is not then weakened by 
many inlets from frefh wounds, but is wholly 
exerted in drawing fap from the root. Whereas 
on the other hand, when a luxuriant tree is 
pruned late in the fpring, the force of its leaves 
to attraft fap from the root will be much fpent 
and loft at the feveral frefh-cut inlets. 

Befides, the early pruned tree being eafed 
of feveral of its twigs or branches, has thereby 
the advantage of ftanding through the whole 
winter, with a head better proportioned to its 
weak root. And fince by Exper. 16. the fap 
is found to afcend in the winter, lefs of that 
Than cold crude iuice is drawn thro' the roors 


77)e Conchjion. 373 

and ftem, to fupply the perfpiration of the 
remaining boughs, whereby the fap of the 
tree is probably lefs depauperated than it 
would have been, if all the boughs had re- 
mained on. For thefe reafons early pruning 
fhould, in the main, and excepting fome 
cafes, be better than late. 

And the reafonablenefs of this pfa&ice is 
further confirmed by the experience of fome, 
who have found, that by pruning Vines, and 
pulling all the leaves off them in September^ 
as foon as the fruit was off, they have borne 
greater plenty of Grapes than other Vines, 
particularly in the year 1726. when, by reafon 
of the extreme wetnefs and coldnefs of the 
preceding fummer, the unripe {hoots produe'd 
generally very little fruit. But early pruning 
feems to be the more preferable, becaufe pull- 
ing off the leaves may poffibly both wound 
the adjoining bud, and injure it, by depriving 
it of the nourifhment which the leaf would 
have brought to it. 

From many Experiments in the fecond 
Chapter, the Gardener will fee with what 
force his grafts imbibe fap from the ftock, 
efpecially that dudlile nourifhment from be- 
tween the bark and wood -, which correfpond- 
ing parts he well knows, by conftant expe- 


$74 %*b e Conchjion. 

rience, muft be carefully adapted to each 
other in grafting, thofe grafts being always 
beft, whofe buds are not far afunder, viz. 
becaufe their expanding leaves can therefore 
draw up fap the more vigoroufly. 

The great quantities of moiflure, which 
we find by Experiment 12. are imbibed at 
wounds where branches are cut off, (hews 
the reafonablenefs of the caution ufed by many 
who are defirous to preferve their trees, viz. 
either by plaiflering or covering with Sheet- 
lead the very large wounds of trees, to defend 
their trunks from being rotted by the foaking 
in of rain. 

And from the fame 12th Experiment a 
hint may be taken to make fome attempts to 
give an artificial tafte to fruits, by making 
trees imbibe in the fame manner fome ftrongly 
tinged or perfumed liquor, which is not fpi- 
rituous : for that, we fee, will kill the tree. I 
have made the ftem of a branch of a tree im- 
bibe two quarts of water without killing it : 
If any are defirous to make this Experiment, 
they mould take care to cut the flump which 
is to imbibe the liquor as long as they can, 
that there may be the more room, from time 
to time, to cut off an inch or two of the top, 
when it is grown fo faturate with liquor, that 
more will not pafs. Tho* 


The Conchjion. 375 

TW Ever-greens are found to imbibe and 
perfpire much lefs than other trees, yet is the 
quantity they perfpire fo confiderable, that it 
has always been one of the greateft difficulties 
in the ordering of a Green-houfe, to let in 
frefh air enough without expofing the plants 
to too much cold. For fince the perfpiration 
of trees will not be free and kindly in a clofc 
damp air, the fap will be apt to ftagnate, 
which will make the plants grow mouldy, 
or they will be fickly, by imbibing fuch damp 
rancid vapours : For by Mr. Millers curious 
obfervations on the perfpiration of the Plan- 
tain tree of the JVejI-Indies, and of the Aloe 
under Experiment 5. plants will often imbibe 
moifture in the night, as well in Stoves as 
common Green-houfe, without fire; it is cer- 
tainly of as great importance to the life of 
the plants to difcharge that infedted rancid 
air, by the admittance of frefh, as it is to 
defend them from the extreme cold of the 
outward air, which will deftroy them, if let 
in immediately upon them. It feems there- 
fore to be a very reafonable method which 
fome ufe, viz. to cover fome of the inlets of 
their Green-houfes on all fides with canvas, 
and in extreme cold weather with fhutters 
made of reed or ftraw, thro* which the air can 


376 The Conchjion. 

only pafs in little ftreams: The like contri- 
vance would probably alfo be of good fervice 
to purify gradually the thick rancid fumes 
which arife from the dung of hot beds, and 
are often very defrru&ive of the tender plants: 
This is to imitate Nature, which, while (he 
provides for the defence of living creatures 
againft: the cold, by a good covering of Hair, 
Wool, or Feathers, at the fame time (he takes 
care that the air may have admittance thro' 
innumerable narrow meanders, in fuch quan- 
tities, as may be fufficient to carry off the 
perfpiring matter. 

. I have here, and as occafion offered, under 
feveral of thp foregoing Experiments, only 
touch'd upon a few of the mod: obvious in- 
ftances, wherein thefe kind of refearches may 
poffibly be of fervice in giving us ufeful hints 
in the culture of plants : Tho' I am very itn- 
fible, that it is from long experience chiefly 
that we are to expert the mod certain rules of 
practice ; yet it is withal to be remembred, that 
the likelieft method to enable us to make the 
moft judicious obfervations, and to put us upon 
ithe moll: probable means of improving any art, 
is to get the bed infight we can into the nature 
#nd properties of thofe things which we are 
defirous to cultivate and improve. 

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